Modern Concept Science and Technology 10

96 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 97ACTIVITY 2Make a PowerPoint file to educate your classmates about the use of genetic technology in agriculture. Potential issues of genetic technologyi. Loss of natural breeds of organism.ii. Genetically modified organisms take over local ecosystems.iii. Loss of biodiversity.iv. Use of biological weapons in war.v. Human cloning, genetically modified humans etc. Measures against genetic technology i. The cloning of humans is banned.ii. Some countries have banned genetically modified crops and cattle.iii. Genetic modification of human foetus is illegal. DNA testing DNA of each species and each individual of that species is unique because the nucleotide of each species or each individual of that species is unique with different qualities. Therefore, we can analyse the components of DNA and its sequences. It helps to identify species and their individuals exactly. The act of analysing DNA components, sequences or mutations is called DNA testing. It can tell us sex, genetic disorders, physical traits, body size, ancestry and many other things about that living thing. DNA testing is popularly used in forensic science, identifying ancestors, identifying parents, solving criminal cases etc. DNA testing is a very complicated technology. It could go wrong and it cannot give accurate information if we make the slightest error. It is highly sensitive work. We should be extra cautious while collecting samples for DNA testing because any impurities or contamination in the sample could lead to wrong or unfair results. FACTS WITH REASONDuring IVF doctors use DNA testing on embryos.During IVF doctors use DNA testing on embryos to find out if there are any genetic disorders. ACTIVITY 3Make an audio-visual material to educate classmates on DNA testing.Role of DNA testingDNA testing is used for identifying species of fossils, identifying males or females, diagnosing genetic disorders, criminal investigation, making vaccines etc. DNA testing can be used to find guilty persons involved in theft, robbery, rape, murder and any other cases. MEMORY TIPSThe Central Police Forensic Science Laboratory (CPFSL) of Nepal Police started DNA testing in Kathmandu in 2015. MEMORY TIPS

98 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 99DNA testing is used for forensic science. DNA testing can accurately identify the person. So, DNA-containing materials collected from the crime scene such as blood, sweat, nails, hair, saliva, etc. can be tested and compared with the DNA test of the suspect. After analysing the results of comparing these two reports, criminals can be identified. Activity Can DNA tests find the ancestry of a person? Discuss. Breeding Reproduction is one of the main characteristics of living things. It allows them to produce offspring similar to themselves. It helps them to continue their species. The process of producing new offspring by any organism is called reproduction. Organisms usually breed in spring because the weather is nice and food is easily available in spring. Breeding is the process by which living things mate and produce their offspring. Breeding can be natural or artificial. Natural breeding means the plants and animals breed on their own in the wild. Artificial breeding means, human beings select a particular breed or species of plants and animals and use them for breeding. It is also called selective breeding. FACTS WITH REASONMost wild animals breed in spring.Organisms usually breed in spring because the weather is nice and food is easily available in spring. ACTIVITY 4Visit a cow farm and try to know which breed of cow they usually prefer for breeding.Selective breedingSelective breeding is common in agriculture and animal husbandry. Farmers have been using it for ages. There are many breeds of the same species all over the world. Some breeds are better at surviving in colds and some breeds are better at surviving in warm places. Some breeds give more meat or fur or milk or eggs. So, farmers usually choose either male or female or both from different breeds and breed them to produce new hybrid organisms with desired characteristics. Such a process is called selective breeding. The process in which humans identify certain special traits in an organism and take steps to breed them so that a new organism will have those traits is called selective breeding. Selective breeding is called artificial breeding because human beings intentionally interfere in breeding. However, selective breeding is still a natural reproduction. Just a breeding partner is chosen but no modern technologies, reproductive assistance or genetic technology are used in it. Selective breeding uses a variation of genes present naturally in various breeds of species. Artificial breeding can lead to the artificial evolution of organisms. MEMORY TIPS

98 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 99Advantages of selective breeding i. It helps to produce organisms with useful desired traits.ii. It helps to improve agriculture by choosing good traits of plants.iii. It helps farmers to develop disease resistance plants or animals. iv. It can help to bring back extinct species. Demerits of selective breeding i. Hybrid organisms produced from artificial breeding can take over natural ecosystems and cause imbalance.ii. Almost all animals or plants of that population will be genetically the same. They do not have variation. So, infectious diseases can kill all of them at once. iii. Natural, local breeds might go extinct because farmers keep hybrid organisms only.iv. Some organisms might go extinct because the local breed is lost earlier due to selective breeding and hybrid organisms are lost due to natural selection because they have bad traits.v. Selective breeding includes inbreeding, where many recessive characters appear in organisms. As a result, many congenital genetic diseases (genetic diseases since birth)FACTS WITH REASONSelective breeding can cause a loss of biodiversity.Each breed of the same species is adapted to survive in their natural habitat. Humans select either male or female or both for selective breeding so that they can insert desired traits in that species of plants or animals. It is artificial selection. Farmers are attracted to keeping hybrid organisms because it gives better products. Therefore, local breeds are almost or already extinct. In addition to that, it is not guaranteed that only favourable traits are transferred to offspring. Sometimes unfavourable traits are collected in the offspring. Those hybrid offspring with unfavourable organisms cannot survive the weather or disease of that particular place and might go extinct. Hence, we can conclude that selective breeding can sometimes cause a loss of biodiversity. Methods of selective breeding There are multiple methods for selective breeding. Each method has its own merits and demerits. Some of them are discussed below: InbreedingLet’s suppose, there is a goat on our farm and it gave birth to two kids. Let’s say the first one is male and the second one is female. They are genetically very close animals. If these two sibling kids mate with each other after a few months, it is called inbreeding. The breeding between males and females who are closely related genetically is called inbreeding. Inbreeding is a very efficient selective breeding method to produce purebred. Purebred might have been lost due to crossbreeding. Inbreeding helps to recollect the genes and give birth to a pure breed. They are also called inbreds. It helps to retrieve pure organisms. It prevents the loss of biodiversity. Some examples of purebred Selective breeding is also called artificial selection because organisms with desirable traits are selected by humans whereas organisms with undesirable traits might go extinct. There is a human interference in the survival of that species. MEMORY TIPS

100 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 101dogs are golden retrievers, Labrador retrievers etc. Some purebred cats are Persian, Siamese etc. Inbreeding can be harmful for farmers because it can collect the most recessive characteristics in the organism. It will make organisms violent and physically weak and congenital genetic diseases will be seen in them. They cannot survive well in the changing environment. FACTS WITH REASONIf inbreeding is done multiple times, all offspring will be genetically the same.If inbreeding is done multiple times, all offspring will be genetically the same because since genetically the same organisms are mated, offspring have a very small gene pool to select genes from. Hence, most of them are born with similar genes and give rise to a population of purebreds. ACTIVITY 5If the trait tall is selected by us and if the trait dwarf is rejected by us in the pea plant and those pea plants are used for selective breeding, then the trait tall will appear in offspring but the trait dwarf might disappear or tend to disappear after many generations. Discuss the validity of the statement. Line breedingLet’s suppose, there is a goat on our farm and it gave birth to two kids. Let’s say the first one is female and the second one is also female. Let’s suppose we sold the first one to another farmer and kept the second one. Let’s say after 3 years we have a new female goat which is the 5th generation of the original goat. Let’s say another farmer has a new male goat which is also 5th generation of the same original goat. These two goats, one male and another female are relatives but very distant genetically. They contain different gene pools because they are born from different parents. They are many generations apart. If we breed them, it is called line breeding. The breeding between males and females who are distantly related genetically is called line breeding. Line breeding is beneficial for farmers because it helps to collect better traits in offspring. Since both breeding pairs have different variations of genes, offspring can choose genes from a greater gene pool. So, offspring can survive better in the environment, adapt easily, do not have reduced physical ability, do not contain congenital genetic disorders, does not contain many recessive traits. It cannot produce purebreds though. Local purebreds can be lost forever.Self pollinationThe flower is a reproductive part of the flowering plants. The stamen is a male part and the carpel is the female part. The stamen has an anther where pollen grains are produced. The carpel has ovules which contain female gamete. The pollen grains should reach the egg for fertilization. The insects, air, water, birds etc help in pollination. Pollination is a process in which the pollen grains are transferred from another to the stigma. The pollination can sometimes go from anther to stigma of the same flower or anther to stigma of a different flower of the same plant or go from anther to stigma of a different flower of a different plant. The process in which the pollen grains transfer from the anther to the stigma of the genetically

100 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 101same flower, is called self-pollination. It is similar to inbreeding. The newly formed seeds contain similar genetic make-up. Therefore, most of the new seedlings after germination will be identical to the mother plant. It is used to obtain purebred plants. It helps to prevent the extinction of purebred local plants from the country. Cross breedingLet’s suppose we have a cow in our house and we decided to breed it with a buffalo, it is called cross-breeding. It gives birth to a hybrid species called beefalo. The cow is a different species from the buffalo but they belong to the same genus. The breeding between two different species of the same genus is called cross-breeding. Most species of the same genus cannot mate to successfully breed but some can. The hybrids are the offspring produced by cross-breeding which has different genetic make-up. Most hybrids produced from cross-breeding are infertile because they have defective sex chromosomes. For example, the mule is an infertile hybrid of a horse and a donkey. However, some of them are fertile because they receive functional sex chromosomes. For example, beefalo are fertile hybrids of bull and buffalo. Mule : Horses and donkeys are different species of animals but they belong to the same genus. They can have offspring together. When a male donkey and a female horse breed and have a baby, it's called a mule. They can't produce babies themselves. They are sterile because they have defective sex chromosomes. They have good traits of the donkey such as they're strong enough to carry heavy things and they also have a good trait of a horse that they can run fast. So, farmers raise mules because they can carry heavy loads and run faster. Hinny: Horses and donkeys are different species of animals but they belong to same genus. They can have babies together. When a female donkey and a male horse breed and have a baby, it's called a hinny. They are sterile. They are similar to mules. Liger: When a male lion and a female tiger breed and have a baby, the result is called a liger. Notably, ligers are bigger than both of their parents in size. Their behavior is more similar to that of a lion than a tiger. They have a distinctive fur coat, which combines elements from both lion and tiger genetics, creating a truly unique and striking appearance. They are infertile and cannot naturally breed in wild. Tigon: The offspring resulting from the crossbreeding of a male tiger and a female lion is known as a tigon. In contrast to their larger parents, tigons tend to be relatively small. Visually, they often resemble tigers, but interestingly, their behaviour such as roaring, feeding habits and socialization is more similar to that of lions. They are also infertile. Beefalo: The hybrid produced from the mating of an American Bison and a domestic bull is known as a beefalo. Unlike some other hybrids, beefalos are Figure: MuleFigure: HinnyFigure: LigerFigure: TigonFigure: BeefaloMost crossbreds such as mules are infertile because of defective sex chromosomes. MEMORY TIPS

102 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 103generally fertile, allowing for further breeding. This crossbreeding is commonly undertaken to enhance meat production, combining desirable characteristics from both the bison and bull, resulting in a hybrid that provides a balance of qualities for meat consumption. Zebroid: The hybrid resulting from the crossbreeding of a zebra and a horse is known as a zebroid. Typically, zebroids are sterile, meaning they are unable to reproduce. Zebroids showcase a fascinating blend of zebra and horse characteristics, often featuring distinctive striped patterns inherited from the zebra parent. Pomato: The hybrid obtained from a tomato and potato is known as a pomato. This unique plant exhibits a fascinating combination of traits, producing tomatoes above the soil and potatoes beneath the soil. Through careful grafting, the pomato plant is created, showcasing the ability to yield two different edible crops. This innovative approach allows for dual harvests, offering both tomatoes and potatoes from a single plant, providing a creative solution in agricultural practices.The pomato plant is a grafted plant. It is not a hybrid or cross-bred plant. MEMORY TIPSAdvantages of crossbreeding Crossbreeding is a common practice in farming and agriculture. It involves mixing different species to create hybrids with beneficial traits. Here are some key advantages of crossbreeding:Improved Quality: Crossbreeding helps enhance the quality of both plants and animals. This means farmers can get more valuable products from their farms.Strength through Diversity: By crossing local breeds with foreign breeds that have desirable traits, the resulting offspring become stronger and more resilient.Elimination of Weak Traits: When two different species are crossed, it can help eliminate or reduce weak traits present in each species, leading to more strong and healthier offspring.Heterotic Qualities: Crossbred animals are heterotic, meaning they possess improved biological qualities. This includes better weight, height, adaptability and resistance to diseases. In essence, crossbreeding results in hybrids with enhanced characteristics.FACTS WITH REASONSCrossbreeding can increase agricultural production. Crossbreeding can increase agricultural production because crossbreeding combines desirable traits from different species, leading to improved adaptability, resilience and overall productivity in plants and animals.Figure: ZebroidFigure: PomatoWe can create plants or animals of the desired trait by using crossbreeding. MEMORY TIPS

102 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 103ACTIVITY 6Are all offspring produced from crossbreeding similar? Find out. Disadvantages of crossbreeding Crossbreeding can be performed by anyone. We can just find a male and female of two different species, breeds or varieties of plants and animals and breed them together. As a result crossbreeding occurs. It occurs between various organisms naturally without human aid too. However, it is better if professionals handle crossbreeding because many things can go wrong while crossbreeding.Some disadvantages of cross breeding are:i. People might crossbreed organisms randomly. It could lead to unethical experiments in cross-breeding. So, strict rules must be made regarding crossbreeding.ii. Physical traits of the crossbreds cannot predicted accurately.iii. Since various traits are collected in organisms, the purebred can go extinct.iv. The traits of parents are not transferred to children properly, so many traits will be lost.v. Agricultural products from crossbreds must be sold cheaper. It could hurt farmers. For example, the meat of broiler chicken must be sold at a cheaper price than the local hens.vi. Some crossbreds can survive better in the ecosystem. They take over the ecosystem and local species can go extinct.In vitro fertilization (IVF)In-vitro fertilization is an assisted reproductive technology to help infertile people become parents. Some of us could not be able to give birth to our children because of certain problems. For men, the cause of infertility could be no sperm production, underdeveloped testicles, very narrow vas deference, low sperm count, immotile sperm or other medical conditions. For a female, the causes of infertility could be underdeveloped ovaries, very narrow fallopian tubes, cysts in the uterus and other medical conditions. Infertility in men as well as females can also be caused by genetic disorders. Infertility is a tragic problem for us all. Sometimes, even if the male has a normal sperm count, motile sperm, healthy uterus or even if the female has a normal ovulation cycle, regular fallopian tube and healthy uterus, they might still be unable to give birth because of unknown reasons. In such desperate situations, in-vitro fertilization can help them bear the child. Invitro fertilization is the assisted reproductive technology in which sperm and ovum are harvested, fertilized in a petri dish and then the embryo is introduced in the uterus.Procedure of IVFFirst of all, the ovary and testicles are stimulated by medicine. Then at the right time, the ovum and sperm are collected by doctors. Sperm is washed and kept in a petri dish. Ovum is also placed in Petri dish. Then doctors carefully fertilize the egg to make zygotes. Zygotes will change into embryos. Such babies are called test tube babies. Doctors perform multiple tests Children born from IVF will have different traits from their parents if donated gametes are used. MEMORY TIPS

104 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 105including DNA tests on embryos to make sure the embryo is healthy. Then the healthy embryo is introduced into the uterus after a few days. The embryo will start to grow into the foetus in the uterus. Hence, invitro fertilization is completed. It usually takes three weeks to complete a cycle. Sometimes they use more than one embryo to increase the success rate of in-vitro fertilization. The child will grow normally as in a regular pregnancy. If any problem arises, in-vitro fertilisation can take a longer time. Sometimes it can fail. If IVF using sperm and ovum of the couple fails, then they can use donated sperm or ovum or both from known or unknown healthy donors. Fertility clinics can provide male gamete or female gamete if required. They have it stored in a sperm bank. History of IVF Back in the day, a British doctor named Patrik Steptoe and a scientist named Robert Edwards teamed up to figure out in-vitro fertilization (IVF) stuff for many years. Finally, in November 1997, they had a volunteer named Lesle Brown. She gave her eggs and her husband gave his sperm. They mixed them together in a dish, and an embryo was made! After a few days, they put the tiny embryo into Lesle's uterus. She got pregnant, and on July 25, 1978, the baby was born by caesarean section. This newborn person was named Louise Joy Brown, the very first test tube baby ever. Louise made history as the first person born using IVF.Jumping to 2004, in Nepal, at Om Hospital, the IVF centre was started. The first IVF baby in Nepal, Om Mani Tamang, entered the world on March 3, 2005. Proud parents Rajendra Tamang and Sandhya Tamang welcomed the little one, marking the beginning of IVF in Nepal.FACTS WITH REASONSIn vitro fertilization is a boon for infertile couples.In vitro fertilization is a boon for infertile couples because it helps them to be parents despite defective gonads and genetic problems. ACTIVITY 7Find out facts and knowledge about in-vitro fertilization. Importance of in vitro fertilizationi. DNA testing is done in embryos to check for genetic disorders. So, it helps to produce children without genetic disorders.ii. It helps people with genetic problems and very low fertility to become parents.iii. It has a greater success rate than other assisted reproductive programs. iv. It treats infertility and other genetic problems.v. Same-sex parents can be blessed with a child by using donated gametes. Figure of IVFHysterosalpingography is a special X-ray of internal female reproductive organs which is used to see the reproductive tract and find out any problems. MEMORY TIPS

104 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 105Disadvantages of in vitro fertilization i. IVF can fail. Multiple cycles may be required for successful pregnancy. So, it will be very time-consuming, inconvenient and expensive.ii. There could be many side effects of IVF due to the use of stimulating drugs and other medications.iii. The child could be underweight.iv. Premature birth is common.v. Since multiple embryos are used to increase the chance of successful pregnancy, many foetuses may be formed inside the uterus at once.vi. Embryo could accidentally be planted outside the uterus at the vagina. It will cause health issues.vii. It could stress couples emotionally and ethically. Artificial insemination Artificial insemination is an assisted reproductive technology. It helps the infertile couple to bear the child. The concept of artificial insemination is to collect, wash and store sperm in the sperm bank and use it to fertilize a female at a suitable time. It can be used to treat infertility in human beings. However, artificial insemination is more popular in animal husbandry, especially cow, yak and buffalo. The procedure of artificial inseminationMale gamete from the healthy person should be collected. The male gamete should be washed and stored in a sperm bank. When ever needed, doctors use the stored sperm or freshly donated sperm to fertilize female. The sperm is put in a sterilized syringe and then introduced at the cervix inside vagina or put directly into the uterus. The process in which sperm collected from the desired male is inserted into the reproductive tract of a female at a suitable time is called artificial insemination. The sperm will now travel up to the ovum and fertilize. The zygote will form and grow normally in the uterus. The foetus will grow naturally like in a natural pregnancy. There will be no physical or mental problems with children. If the raw unwashed sperms or donated sperms from a sperms bank are introduced into the vagina it is called intracervical insemination. If the washed sperm is introduced directly into the uterus, it is called intrauterine insemination.History of artificial inseminationItalian scientist Lazzaro Spallanzani realized that the capacity to fertilize an egg lies in the microscopic sperms floating in the semen but not in the transparent liquid part of the semen. So, he washed the semen to increase the concentration of sperm. He introduced it in the reproductive tract of the female dogs. The female dogs got pregnant and gave birth to puppies. Hence, artificial insemination technology was discovered. The objective of artificial insemination is to collect the sperm of healthy, good-quality males, store it and use it to Figure of AIA sperm bank is a place where semen is kept in cold storage for use in artificial insemination.MEMORY TIPSOffspring produced from artificial insemination are normal without any physical or mental side effects. MEMORY TIPS

106 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 107fertilize a large number of females at a suitable time to produce a large number of hybrid offspring of better genetic quality. It is a very popular assisted reproductive technology in animal husbandry. FACTS WITH REASONArtificial insemination increases the genetic quality of the animals in animal husbandry.Artificial insemination increases the genetic quality of the animals in animal husbandry because the farmers can select the sperm collected from the best male with better genetic qualities and use it to fertilize female animals. ACTIVITY 8Discuss the importance of artificial insemination for farmers. Conditions when doctors suggest artificial insemination are if:i. The patient is suffering from endometriosis. ii. If the sperm count is low.iii. If sperm mobility is less.iv. If sperm cannot penetrate the cervix. v. If males are dead or unavailable.Advantages of artificial insemination i. It helps the infertile couple to bear the child. ii. It helps to treat infertility and increase the rate of fertilization.iii. It allows farmers to fertilize their cattle with sperm of good genetic quality. iv. The sperm are collected, tested and stored to guarantee the fertility of sperm.v. Sperms are stored in a sperm container. So, it is easy for transportation anywhere at any distance for insemination. vi. Sperm stored in a sperm bank can be used even if the male is dead or unavailable.vii. Farmers do not need to keep male cattle. So, it saves them money. They can sell male cattle for meat. FACTS WITH REASONGloves, syringes and other equipment should be properly sterilized during artificial insemination. Gloves, syringes and other equipment should be properly sterilized during artificial insemination to avoid infection and to reduce chances of failure. Infected equipment can infect the vagina and uterus and prevent pregnancy. Disadvantages of artificial insemination i. Farmers cannot do it themselves. A trained vet doctor is required to do it.ii. It can fail sometimes. So, it is inconvenient and needs to be repeated. It wastes their money.iii. The infected hand and tools can infect the reproductive tract and prevent pregnancy.iv. It takes longer time than natural pregnancy.

106 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 107HOT SKILL HIGHER ORDER THINKING SKILL1. Do changes in genetic make-up affect the traits of organisms? Yes, the changes in genetic make-up affect the traits of an organism because genes contain characteristics that determine our bodies. The changes in genes can easily alter physical appearances, disease resistance, physical abilities and intelligence. 2. Can DNA testing be used to solve criminal investigations? DNA testing is a technology which is used to count chromosomes and identify changes in genes and genomes. It can be used to identify a person accurately. So, if there is any material collected from the crime scene that contains DNA, the DNA testing can exactly tell who the criminal is or is not. The sample from the crime scene such as blood, sweat, nails, hair, saliva, etc. are sent to the laboratory. The DNA test is carried out to identify the criminal. DNA testing of the suspect is also done. Two reports are tallied to see if the suspect is guilty or not. 3. The cattle produced from inbreeding were sick and weak. When a cow and bull were mated that were separated by a few generations, the offspring were healthy. Discuss the reasons. The cattle produced from inbreeding were sick. The main reason for sick cattle from inbreeding is they have a very small gene pool. But when a cow and bull were mated that are a few generations apart, the offspring were healthy. It is because they are a few generations apart and they contained a larger gene pool. In this process, the better dominant characteristics appeared in the offspring. 4. Utshav bred mules but unfortunately no offspring were produced. Utshav bred mules but unfortunately no offspring were produced because mules are crossbreds. They have defective sex chromosomes. 5. An adopted child wanted to know his real parents. Which technology will help him?If an adopted child wants to know his real parents, he can use DNA testing genetic technology. He has to test his DNA and test the DNA of suspected persons. If the DNA test matches, they are his parents. 6. DNA is very important for genetic engineering. DNA contains genes. The genes contain hereditary information. If a genetic engineer knows about the structure of DNA, function of DNA, chemical composition of DNA, construction of DNA, molecular bonds in DNA and any other knowledge about DNA, that genetic engineer can cut, merge, transfer, combine, insert or even artificially create DNA. This technology can be used in medicine, agriculture, animal husbandry, gene therapy etc. Hence genetic engineering involves the detailed study of DNA. 7. Line breeding is better than inbreeding.Line breeding is better than inbreeding because inbreeding brings recessive traits and sickness in offspring but linebreeding does not. Line breeding collects desired traits only. 8. Artificial Insemination (AI) technology is beneficial for farmers. Artificial Insemination (AI) technology is beneficial for farmers because:i. They do not need to keep bulls and goats so it will reduce their expenses. They can also sell those animals.ii. They can freely choose the healthy male gamete of good breeds of animals to fertilize their cows or goats. iii. Artificial insemination is cheaper for farmers.iv. Artificial insemination has a higher success rate than using real ox or goats for fertilization. v. It’s easier and more convenient to carry male gamete containers than to transport real cows and goats. vi. Offspring produced from artificial insemination has better characteristics.

108 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 1099. Artificial insemination is preferred by farmers for their cattle. How is it done? The concept of artificial insemination is to introduce sperm into a female’s cervix or uterus. In this case, let’s assume we are going to perform artificial insemination in cows. So, for artificial insemination healthy male gamete from the desired breed of cow should be collected. The male gamete should be washed and stored in a sperm bank. Then when required vet doctor will bring it to the farmer. Then the vet will keep it in a sterilized syringe and use the syringe to place the male gamete near the cervix of the female cow. In case the artificial intracervical insemination fails the bet will then place the male gamete directly into the uterus. The intrauterine insemination has more success rate than intracervical insemination.Hence, artificial insemination is used for fertilization of cattle. 10. Explain the importance of genetic engineering.The importance of genetic engineering is listed below:i. Transgenic technology, gene expression and molecular markers technology are used in agriculture.ii. DNA testing is used in solving criminal cases and identifying parents and ancestorsiii. Genetically modified crops and animals are used in agriculture and animal husbandry. iv. Gene therapy can treat various genetic disorders. 4 STEPS EXERCISE EXERCISESTEP11. Multiple Choice Questions a. What is a hysterosalpingogram? i. x-ray dye test to diagnose a coronary blockage ii. x-ray dye test to diagnose problems related to fertility in females iii. x-ray test to test for fissures in bone iv. x-ray machine gun b. If two cattle from the same parents bred together, what is it called?i. cross breeding ii. artificial insemination iii. linebreeding iv. inbreeding c. What does genetic modification do?i. alter the physical abilities of an organism.ii. determine the gender of the organism iii. genetic modification does not affect the body of an organismiv. treat common cold and diarrhoea d. What is the procedure of artificial insemination? i. bring a local breed of cow → bring a better breed ox → cross them naturally ii. stimulate ovaries of females → collection of zygotes from males → introduce sperm into the female reproductive tractiii. stimulate gonads of male and female → collect egg and sperm → fertilize in Petri dish → introduce embryo in the female reproductive tract

108 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 109iv. stimulate ovaries of female → collection of semen from male → introduce sperm in the female reproductive tracte. Blood sample from the crime scene is collected. DNA samples of three suspects are also collected. DNA is isolated. DNA segments are cut from isolated DNA. DNA segments are now sequenced. The result is displayed below. Who is the criminal?i. Suspect 2 ii. Suspect 3iii. victim and suspect 3 iv. Suspect 1 f. What does X represent in the given concept map?X genes Genetic technology study Cut, mergedi. genetic engineer ii. geology iii. genetics iv. genetic modification g. Ganga is different from her twins. Which process brought these differences? i. inheritance ii. heredity iii. evolution iv. variationh. Study the given statement and arguments and select the best comment. Statement: Crossbreds are made to increase disease resistance and adaptability in organisms. It increases agricultural production.Argument 1: Crossbreds are unable to breed naturally. Argument 2: That’s not entirely true. Some crossbreds can breed naturally and increase their population.i. Statement and argument 2 are incorrect. Argument 1 is correct. ii. Statement and argument 2 are correct. Argument 1 is incorrect. iii. The statement is correct. Argument 1 and argument 2 are incorrect. iv. Argument 1 and argument 2 are correct. The statement is wrong. i. Which assisted reproductive program is being discussed below? Natural breeding Assisted reproductive program Fertilization Reproductive tract receives No Yes Outside the female body Embryo i. Selective breeding ii. intrauterine insemination iii. intracervical insemination iv. in-vitro fertilization j. What set of chemicals makes DNA? i. nitrogen base, deoxyribose sugar and phosphate ion

110 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 111ii. protein and ribosomes iii. gene and protein iv. nitrogen base, sugar and phosphate a. ii b. iv c. i d. iv e. ii f. iii g. iv h. ii i. iv j. iAns of MCQSTEP22. Very short questions a. Which one is a liger? Father lion Father tiger Mother lion A BMother tiger C D b. Write the name of the process X.X BAssisted reproductive technologySperm is introduced in female reproductive tract Embryo is introduced in female reproductive tractc. Why is genetic technology used in agriculture? d. Who is a genetic engineer? e. What is self-pollination? f. Who and when successfully performed artificial insemination? g. When is in vitro fertilization suggested to the couple? h. Offspring from crossbreeding are mostly infertile. Give reason. i. Which assisted fertility program is suggested to the couple if one of them has a genetic disability that is preventing them from breeding? STEP33. Short questions a. Inbreeding is not good for humans. Explain. b. Differentiate between line breeding and inbreedingc. Traits of children born from in vitro fertilization may or may not match with parents. Give reason.d. The cattle produced from inbreeding were sick and weak. When a cow and bull that were separated by a few generations were mated, the offspring were healthy. Discuss the reasons. e. Beefalo is a hybrid of American bison and an ox. What is the act of producing beefalo called? Why is the beefalo breed reared? f. Artificial insemination in cattle has helped to improve the economy of the country. Justify.

110 genetic te cHnology Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 111g. How has selective breeding helped to improve food security?h. A mule cannot give birth. Why? STEP44. Long questions a. Answer the following questions based on the given figure.i. Which assisted reproductive technology is shown in the diagram?ii. Under what condition this technology is preferred? Write any two.iii. Why are sperms washed within one hour for this process?b. Mr. Bhakta is an infertile man. He wants to have some kids with his wife. He has already tried many herbs and Ayurvedic medicines. He has also prayed and visited wizards but all in vain. What suggestions can we offer him so that he will be a father of some children?c. Miss Arushi wants to be a mother. She is considering conceiving through artificial insemination. Explain possible risks of artificial insemination and suggest some methods to avoid those risks.d. How has genetic technology helped human civilization? Discuss its importance. e. Read the given conversation and answer the following questions. Two friends, Sharmila and Pramila went to Ramila to celebrate Elle’s birthday. Sharmila : Children are a blessing, aren’t they? I wish I had a lovely child like yours. But I do not want to get married!Ramila : Sharmila! I would like to interest you in artificial insemination. Fertility clinics can provide you with healthy sperm. Pramila : Some people find it unethical and we might get uterus infection from it. Ramila : Yeah! You are right. Unsterilized tools can cause infection. AI might fail as well. After all, I am not able to conceive through artificial insemination. Doctors used a hysterosalpingogram to check my issues with fertility and found that my both fallopian tubes were narrow.Pramila : Ramila! You should definitely try IVF because Elle is also born that way. She is a test tube baby. My husband’s sperm count was too low. So, we used this assisted fertility program to be parents. IVF is really a blessing.i. Why does Pramila say that Elle is a test tube baby? ii. Pramila said that IVF is a blessing for them. Explain the reasons.♦♦♦

112 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 113Key terms and terminologies of the unit1. Circulatory system: The human circulatory system is the organ system in the human body which is responsible for the distribution of blood all over the body to supply the necessary materials to cells and also to collect unwanted materials from the body and send them to the excretory system.2. Blood: Blood is a thick, red, viscous fluid connective tissue in the body.3. Plasma: Plasma is a yellow coloured semi-transparent liquid present in the blood.4. Red blood corpuscles: Red blood cells (RBCs) are red-coloured, biconcave, enucleated structures floating freely in the blood.5. White blood corpuscles: White blood corpuscles (WBCs) are irregular blood cells which have nucleus and other cell organelles.6. Platelets: Platelets are non-nucleated, irregular, colourless, round or oval blood cells found freely suspended in the blood plasma.7. Anaemia: Anaemia is a condition which is caused due to the lack of RBCs or haemoglobin in the blood. 8. Haemophilia : Haemophilia is a condition in which blood clotting delays in the cuts and wounds due to the absence of blood-clotting chemicals.9. Leukaemia : The blood-related disease caused by to excessive number of WBCs than average is called leukaemia. It is also called blood cancer. Sequence of Curriculum Issued by CDC Introduction to the human blood circulatory system Structure and function of different parts of human blood circulatory system Blood circulatory system in human body Introduction and identification of blood group  Investigation of heartbeat and pulse Blood pressure, blood sugar and uric acid Heart attack: introduction, causes, measures to control and curative method (angiography and bypass surgery)UNITPhysiological Structure and Life Process5Estimated teaching periods Theory Practical9 3Dr. Bhagwan Koirala, born on October 12, 1947, in Palpa, is a revered figure in the field of cardiothoracic surgery. His remarkable contributions to advancements in heart surgery and medical education have left an indelible mark on Nepal's medical landscape. Dr. Koirala's expertise and surgical prowess have significantly improved patient outcomes, pushing the boundaries of cardiac care in the country. Moreover, his dedication to medical education has been instrumental in shaping the future of cardiac surgery by training the next generation of surgeons. Dr. Bhagwan KoiralaAbout the Nepalese Scientist

112 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 11310. Leukopenia : The blood related disease caused due to fewer number of WBCs than the average is called leukopenia. 11. Blood-clotting : The process in which the fibrinogen and platelets make a blood clot by using RBCs to close wounds is called blood clotting.12. Blood vessels : The elastic tubes and pipes through which blood flows are called blood vessels.13. Arteries : Arteries are thick-walled blood vessels that carry blood away from the heart.14. Veins : Veins are the thin-walled blood vessels that carry blood towards the heart. 15. Capillaries : Capillaries are hair-like, extremely narrow and thin-walled blood vessels. 16. Pericardium : The double-layered membranous structure that covers the heart is called the pericardium. 17. Pericardial cavity: The two layers of the pericardium are close to each other forming a gap called pericardial cavity.18. Pericardial fluid : The lubricating fluid present in the pericardial cavity is called the pericardial fluid. 19. Tricuspid valve : The valve between the right auricle and right ventricle is called tricuspid valve20. Bicuspid valve : The valve present between left auricle and the left ventricle is called bicuspid valve.21. Pulmonary valve : The valve present between pulmonary artery and right ventricle is known as pulmonary valve.22. Aortic valve : The valve present between aorta and the left ventricle is known as the aortic valve.23. Blood pressure : The pressure exerted by blood on the walls of the arteries when the left ventricle contracts and relaxes is known as blood pressure.24. Systolic blood pressure : The blood pressure felt in the blood vessels when the left ventricles contracts is called systolic blood pressure.25. Diastolic blood pressure :The blood pressure felt on arteries when the left ventricle relaxes is called diastolic pressure.26. High blood pressure : High blood pressure is a condition in which blood pressure is equal to or greater than 140/90 mm of Hg for more than two days.27. Heart beat : A heart beat is a continuous rhythmic beat throughout the life which is produced due to complete contraction and relaxation of the heart muscle.28. Arterial pulse : The repetitive jerk felt at the major arteries of the body due to the pumping action of the heart is known as the arterial pulse.29. Pulmonary circulation: The type of circulation in which blood flows from right ventricle to the lungs and then to the left auricle is called pulmonary circulation. 30. Systemic circulation : The circulation of blood from left ventricle to the right auricle of the heart through body tissues (except lungs) is called systemic circulation.31. Insulin : Insulin is a hormone secreted by pancreas that helps in glucose utilization and control.32. Diabetes : The condition in which body becomes unable to maintain normal glucose level due to the lack of insulin is called diabetes.33. Uric acid : Uric acid is an organic compound produced from digestion of purine. 34. Gout The disease caused by the deposition of uric crystals in the soft spongy bone tissues at joints is called gout.35. Heart attack : The condition in which the flow of oxygenated blood into the heart tissues is called heart attack. 36. Bypass surgery: Coronary artery bypass surgery is the process of making an alternative path to supply oxygen-rich and nutrient-rich blood in the tissues of the heart around the blockage. 37. Angiography: Angiography is a technique to diagnose a heart attack by mixing dye into the blood that goes through coronary arteries and using an X-ray machine to take images and locate coronary blockages.

114 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 11538. Polycythemia: The disease caused due to the presence of an excessive number of RBCs is called polycythemia. 39. Haemoglobin: Haemoglobin is a red protein in the blood. It is responsible for absorbing oxygen in the blood. 40. Oxyhaemoglobin: The haemoglobin that carries oxygen is called oxyhaemoglobin. 41. Carboxyhaemoglobin: The haemoglobin that carries carbon dioxide is called carboxyhaemoglobin. 42. Thrombocytosis: Thrombocytosis is a condition in which there is an excessive number of platelets in the blood than the average. 43. Serum: The plasma without fibrinogen is called serum. 44. Blood group: The classification of blood, based on the presence and absence of antibodies and antigens is called blood group. 45. Sphygmomanometer: The device that is used to measure blood pressure is known as a sphygmomanometer.46. Angioplasty: The process of widening or opening the blocked coronary artery is called angioplasty. 47. Hyperuricemia: The higher concentration of uric acid in the blood than the average is called hyperuricemia. 48. Slow heart: If the heart of a person beats less than 60 times per minute, it is called a slow heart. It is also called bradycardia.49. Fast heart: If the heart of the person beats more than 100 times per minute, it is called a fast heart. It is also called tachycardia.50. Angiogram: X-ray images formed during angiography are called angiograms. Human blood circulatory systemLook at the given pictures. What do they suggest to you about circulation of body fluids in human body? Can you suggest why blood oozes out of our body during cuts and wounds as shown in the first picture? What is the doctor doing in the second picture? In the first picture, the red coloured fluid oozing out from the cut in the finger is blood. It oozes out for a couple of minutes and then stops. In the second picture, the doctor is listening the heart sound by stethoscope. The heart continuously beats inside our chest. Why does it beat? All these questions are related to the blood circulatory system of our body. In this unit, we will attempt to answer these questions.Blood oozing out from a cut in fingerDoctor using a stethoscope to listen the heart beat and lungs sound in a childWhen we feel headache, we take a painkiller. After sometime we get relief. This is because the chemicals present in the painkiller reach to the head through blood circulatory system. Similarly, every organism needs food to live. The food we eat is converted into simpler form inside the digestive system. The digested food is absorbed and then mixed in the bloodstream. The nutrients present in the digested food are transported to the different parts of the body

114 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 115through blood circulation. Along with the nutrients, blood circulatory system also conducts oxygen, carbon dioxide, hormone, medicines, waste product, etc. from one part of the body to the next. Thus, The human circulatory system is the organ system in the human body which is responsible for the distribution of blood all over the body to supply the necessary materials to cells and also to collect unwanted materials from the body and send them to the excretory system. The blood circulatory system is also responsible for maintaining constant body temperature, chemical composition, pH value, etc.The blood circulatory system consists of three main parts. They are blood, blood vessel and heart. The heart is the main pumping organ of the blood circulatory system. The arteries, veins and capillaries are the pathways through which blood flows. Similarly, the blood is a main medium to circulate various materials throughout the body. Functions of the circulatory systemi. The heart keeps pumping the blood so that blood flow won’t stop.ii. The blood vessels provide a path for blood to flow so that it can go to different parts and do its work.iii. The blood reaches various parts and helps in transportation, regulation and protection. It transports nutrients, oxygen, enzymes, medicines, drugs, hormones, waste etc. It regulates the body temperature, water level, hormone level, pH level etc. It makes an immunity system to fight microbes, prevent diseases, heal wounds etc. iv. The circulatory system connects the respiratory system, digestive system, muscular system, excretory system and others to keep us alive. BloodBlood is a thick, red, viscous fluid connective tissue in the body. It continuously circulates throughout the body and never stops. Some major characteristics of blood are as follows.i. Colour: The colour of blood is blackish red, scarlet (dark reddish orange) or blue depending upon its type. Pure or oxygenated blood is scarlet in colour while deoxygenated blood is blackish red. But, the deoxygenated blood in veins looks blue from outside because of the reflection of blue light from the walls of the veins. ii. Volume: In an adult, the total volume of blood is about 5.5 litres in average. The total volume of blood depends upon the water content in it.iii. Specific gravity and pH: Blood is slightly heavier than pure water. Its specific gravity or relative density is 1.05 to 1.06. It is alkaline in nature with pH value 7.35 to 7.45.Composition of Blood Blood is a heterogeneous fluid. It is composed of two main components. They are 55% blood plasma and 45% blood corpuscles. Blood corpuscles are of three types. They are red blood Similar to blood circulatory system in human beings, the conducting system made up of xylem and phloem is responsible to conduct water, minerals and food materials in the plants.MEMORY TIPSBlood is slightly heavier than water and slightly alkaline in nature. But we feel salty taste while tasting it.MEMORY TIPS

116 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 117corpuscles (RBC), white blood corpuscles (WBC), platelets.Blood plasma Plasma is a yellow coloured semi-transparent liquid present in the blood. It forms about 55% of the total volume of blood. It contains upto 90% water, 8% proteins and 2% respiratory gases, nutrients, hormones, minerals, salts, carbohydrates, antibodies and other chemicals. Without blood corpuscles, plasma looks yellow coloured. The plasma transports all the dissolved substances in different parts of the body. The blood corpuscles, viz. red blood cells, white blood cells and platelets are immersed in the plasma along with other substances. Functions of PlasmaThere are many functions of plasma. Some of the major functions are listed below:i. Plasma controls the flow and composition of water in the blood. ii. It helps to transport the nutrients to different parts of the body. iii. It helps to transport hormones to the tissues. iv. It helps in carrying urea from the liver to the kidneys. v. It regulates our body temperature, pH value etc. vi. The fibrinogen present in plasma helps in blood clotting.Blood corpuscles or cellsBlood corpuscles occupy about 45% of the total volume of the blood. There are three kinds of blood corpuscles in the blood. They are red blood cells, white blood cells and platelets.Red Blood Cell (RBC) or Erythrocytes Red blood cells (RBCs) are red coloured, biconcave, enucleated structures floating freely in the blood.They carry a red pigment at their centre called haemoglobin. The matured RBCs do not have a nucleus except in camels. The whole blood appears PlasmaRed blood cellWhite blood cellPlateletComposition of bloodSeparation of blood components by centrifugationRed blood cellsWhite blood cellsPlasmaPlateletsBlood vesselBlood cells

116 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 117coloured because there are millions of RBCs in it. A single haemoglobin molecule is made up of 4% haemin (iron) and 96% globin (protein). The function of RBC is to transport oxygen to all parts of the body and to collect carbon dioxide to excrete out into the lungs. There are 45 lakhs to 50 lakhs RBCs in 1 mm3 of blood. In every second, about 20 lakhs RBCs are formed and the same number is destroyed. When RBCs die, their iron content present in haemoglobin is reused by the liver to make a chemical called bilirubin. RBCs are formed in the bone marrow of the bones such as vertebrae, ribs, skull, etc. and die in the liver and spleen. Their average life span is 90 to 120 days. The blood is red because of the presence of red blood cells which contains haemoglobin pigments. The haemoglobin pigments give redness to red blood cells. FACTS WITH REASONOxyhaemoglobin and deoxyhaemoglobinThe blood which carries oxygen is known as oxygenated blood. At the centre of RBC, haemoglobin molecule is present. This haemoglobin molecule combines with oxygen and transports it to the tissue. One haemoglobin molecule can carry up to four molecules of oxygen. The haemoglobin which carries oxygen is known as oxyhaemoglobin.The blood which carries carbon dioxide in the body is known as deoxygenated blood. During circulation, haemoglobin transports oxygen to the cells and receives carbon dioxide from there. The collected carbon dioxide is transported to the excretory organ to eliminate from the body. A haemoglobin can combine with four molecules of carbon dioxide. The haemoglobin that carries carbon dioxide is called deoxyhemoglobin.White blood cells (WBC) or LeucocyteWhite blood corpuscles (WBCs) are irregular blood cells which have nucleus and other cell organelles. They show amoeboid movement in the blood plasma. They do not contain haemoglobin. WBCs are of two types. They are granulocytes and agranulocytes. The white blood corpuscles which have granules in their cytoplasm are called granulocytes or granular leukocyte. There are three types of granulocytes. They are neutrophils, basophilsand eosinophils. Similarly, the white blood corpuscles which do not have granules in their cytoplasm are called agranulocytes or agranular leukocyte. There are two types of agranulocytes. They are lymphocytes and monocytes. In an adult man the number of RBCs ranges from 50 lakhs to 55 lakhs and in an adult woman it ranges from 45 lakhs to 50 lakhs in per cubic millimetre blood.MEMORY TIPSMemory Plus CO is a poisonous gas. If CO binds with haemoglobin, one suffers from a condition known as carbon monoxide poisoning. MEMORY TIPSNeutrophil EosinophilLymphocyteMonocyteBasophilWhite blood cellsWBCs are eukaryotes because they have a nucleus. RBCs and platelets are prokaryotes because they do not have a nucleus. MEMORY TIPS

118 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 119Function of WBCsThe main function of WBCs is to kill microorganism present in the blood. They also engulf the foreign particles and digest them. Sometimes, WBCs cannot digest bacteria or virus or foreign particles. Due to which they explode and die. If significant numbers of WBCs die, we suffer from different diseases. Leucocytes are produced by the stem cells in the red bone marrow and lymph nodes. They are destroyed in the liver, spleen and at a site of infection. There are about 4000-11000 WBCs in 1 mm3 of blood. Their life span is about two weeks or 15 days. In fact, the life span of WBC is not fixed as they may die anytime while fighting with the pathogens.WBCs are called soldiers of the body.WBCs are called soldiers of the body because they produce antibodies, make an immunity system, remove pus and kill germs and parasites. FACTS WITH REASONACTIVITY 1To observe blood clotting and blood film under the microscope1. Wash your hands with soap and water. 2. Take a clean and sterilized lancet and prick your finger to extract few drops of blood. 3. Keep few drops of blood in a petri dish and observe the time taken for the blood clotting.4. Similarly, keep few drops of blood in a slide, spread it using another slide uniformly and leave it to dry. 5. Add some Leishman stain on the blood sample. Then, observe the blood cells under a compound microscope. Platelets or Thrombocytes Platelets are non-nucleated, irregular, colourless, round or oval blood cells found freely suspended in the blood plasma. They are non-nucleated and irregular structures. They help in the blood-clotting in case of cuts and wounds. So, they prevent the loss of blood. In 1 mm3 of blood, there are about 2 to 4 lakh of platelets. Their life span is 2 to 3 days. They are produced in bone marrow and destroyed in spleen.Some blood disordersAnaemiaAnaemia is a condition which is caused due to the lack of RBCs or haemoglobin in the blood.A person suffering from anaemia has pale eyes, face and nails. He/she feels tired even walking a short distance. It is because the blood cannot nourish the muscles with enough oxygen due to the lack of RBCs or haemoglobin. The person suffering from anaemia has following symptoms.WBCs have irregular shaped nucleus. The collection of dead WBCs, tissues, cells or other chemicals inside the tissues or skin is called pus.MEMORY TIPSPlatelets

118 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 119i. tiredness and weakness ii. difficulty breathing and chest pain iii. shortness of breath and headaches iv. Dizziness and irregular heartbeat HaemophiliaThe fibrinogen (it is a type of protein) helps in the blood-clotting with the help of clotting factors. If these chemicals are not produced in the body, the process of blood-clotting delays. It is called haemophilia. Thus, haemophilia is a condition in which blood-clotting delays in the cuts and wounds due to the absence of blood-clotting chemicals. It is a sex-linked disease because it generally affects males. The females are the carriers of this disease i.e. they transfer this disease to the future generation. Haemophilia in females is very rare.LeukaemiaThe blood-related disease caused by to excessive number of WBCs than average is called leukaemia. It is also called blood cancer. It is also called blood cancer. It is caused due to the excess production of abnormal WBCs that cannot be regulated by the body.LeukopeniaThe blood-related disease caused by fewer number of WBCs than the average is called leukopenia. It makes a person susceptible to diseases. It is also caused by viral infection, bacterial infection, HIV, defect in bonemarrow, auto-immune diseases etc.PolycythemiaThe disease caused due to the presence of an excessive number of RBCs is called polycythemia. It causes high blood pressure and headache.ThrombocytosisThrombocytosis is a condition in which there is an excessive number of platelets in the blood than the average. It can cause intravenous blood clot, heart attack and brain strokes.A person suffering from anaemia feels tired on walking a short distance, why?The circulatory system of the anaemic person cannot transport sufficient amount of oxygen to his/her muscles due to the lack of red blood cells or haemoglobin. As a result, muscle cells cannot release sufficient amount of energy for continuous walking. Hence, a person suffering from anaemia feels tired on walking a short distance.FACTS WITH REASONA summary of the comparison among RBC, WBC and plateletsFeature RBC WBC PlateletsShape Biconcave Irregular Oval or roundSize 7 µ 8-15 µ 2.5 µLife span 90-120 days Few hours to 15 days 2-3 daysSite of production Bone marrow Bone marrow and Lymph nodesGiant cells of bone marrow and mostly in lungsPerson suffering from haemophilia does not show blood clotting. As a result, continuous bleeding occurs form the cuts and wounds. MEMORY TIPS

120 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 121Site of destruction Liver and spleen Liver, spleen andsite of infectionSpleenColour Red White colourlessTypes×1. Granulocytes, e.g. neutrophils, eosinophils and basophils2. Agranulocytes, e.g. lymphocytes and monocytes×Presence of Haemoglobin (Hb) andNucleusNon- nucleatedHb presentNucleatedHb AbsentNon-nucleatedHb absentAverage number Females 4.5-5 millions/mm3Males 5-5.5 millions/mm36000-10000/ mm3 in both male and female2-4 lakhs/ mm3Function Transport O2 and CO2 Produce antibodies and fight against pathogensHelps in the clotting of blood Blood disorders caused by excess or deficiency of blood corpusclesExcess polycythaemia leukaemia or blood cancer ThrombocytosisDeficiency Anaemia Leukopenia ThrombocytopeniaClotting of BloodWhen there are cut, wound or tissue damage in the body, the platelets activate themselves and form a thick jelly-like mesh at the sites of cuts and wounds. As a result, bleeding stops. Thus, The process in which the fibrinogen and platelets make a blood clot by using RBCs to close wounds is called blood clotting or blood coagulation. Clotting prevents the further loss of blood from the cut and wound. In general, the duration of blood-clotting is about 4 to 10 minutes.There are dozens of blood-clotting factors and chemicals that take part during blood-clotting process. Blood-clotting does not occur inside the blood vessels because there are a number of anticoagulant proteins in the blood. For example, heparin. The blood-clotting should only occur when there is cut and wound in the body. Otherwise blood supply would cut off in the organs. As soon as there is injury in the blood vessel, the underlying collagen tissues are exposed to the platelets. These platelets bind with collagen tissues making aggregation at the site of wound. With the help of several chemical reactions and clotting factors, prothrombin is converted into thrombin. Similarly, thrombin converts fibrinogen to fibrin and forms a solid mesh-like structure. The solid mesh gathers more platelets and RBCs. As a result, a stable clot is formed. Functions of BloodThe basic function of the blood is to transport gases (oxygen and carbon dioxide), nutrients and waste materials to the desired locations. But, the blood performs variety of other functions which are mentioned below:a) TransportationBlood transports essential materials like water, nutrients, hormones and oxygen to the

120 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 121tissues. It also transports waste substances like urea, carbon dioxide, etc. to the site of excretion. b) ProtectionBlood fights against germs and toxic materials. As a result, it protects body from various diseases. Platelets help in blood-clotting and prevent from loss of blood. c) Regulation Blood maintains body temperature. It regulates the amount of water in the body. It regulates different chemicals like salt, sodium, potassium, calcium, acidity, alkalinity, etc. HeartA heart is a small triangular blood-pumping muscular organ. It is the centre of the blood circulatory system. It is made of cardiac tissue which is the strongest muscle tissue. They are involuntary muscles. Therefore heart cannot be controlled by us. It runs automatically. It weighs about 300 grams. It has a protective layer called pericardium. The coronary artery supplies nutrients and oxygen to it and the coronary sinus removes waste from it. Internally it has four chambers. The upper two chambers are called auricles. They have a thin wall. They collect blood. The lower, larger and thicker chambers are called ventricles. They push blood away from the heart. The heart pumps blood non-stop forever. It is supposed to be the size of the owner's fist. The detailed structure of the heart can be studied in two headings. They are:External morphology of heartThe heart is a three-dimensional conical muscular organ that contracts and relaxes rhythmically. Its morphology can be best studied by having either a model or an actual heart from a dead animal. It is a pumping organ of the body that makes the blood flow through the arteries. It is located between two lungs, in the centre of the chest. The two-third part of the heart is located towards the left. Heart is covered by a double-layered membrane. The double layered membranous structure that covers the heart is called pericardium. The two layers of the pericardium are close to each other forming a gap called pericardial cavity. The pericardial cavity contains a fluid in it. The lubricating fluid present in the pericardial cavity is called the pericardial fluid. Following are the functions of the pericardial fluid:AortaPulmonary arteryPulmonary veinsLeft auricleLeft ventriclePericardium Inferior vena cavaRight ventricleRight auriclePulmonary veinsSuperior vena cavaExternal morphology of heart

122 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 123i. It makes the heart beat smooth.ii. It also prevents the heart from the mechanical shock. The heart has hair-like blood vessels seen externally. These blood vessels are called coronary blood vessels. They carry blood towards and away from its own tissues. Coronary blood vessels are of two types. They are coronary artery and coronary vein. Coronary arteries carry oxygenated blood to the heart tissues and coronary veins collect deoxygenated blood to the heart.Internal morphology or anatomy of the heartThe heart is a four chambered organ. The upper two chambers are called auricles and the lower two chambers are called ventricles. The two auricles are separated from each other by a septum called inter-auricular septum. Similarly, the two ventricles are separated from each other by a septum called inter-ventricular septum. Inside a normal heart, the blood flows only from the upper chamber to the lower chamber. That is, the auricles pump the blood to the ventricles. Then ventricles pump blood to lungs and other parts of the body at a high pressure. Thus, ventricles are more muscular than auricles. Among the two ventricles, left ventricle has to pump blood to all parts of the body at longer distance while the right ventricle has to pump the blood to the lungs at a shorter distance. Thus, the left ventricle is more muscular than the right ventricle. Heart has various blood vessels that end at it or start from it. There are mainly four apertures or passages in the heart that end or start in the four chambers. Heart and the four chambersa) Right auricle The right auricle is the upper right chamber of the heart. It is responsible for collecting deoxygenated blood from all over the body. Altogether, three blood vessels end in the right atrium. They are superior venacava, inferior venacava and the coronary sinus. The superior venacava collects deoxygenated blood from the upper parts of the body like neck, brain etc. while the inferior venacava collects blood from the lower parts of the body like legs, liver, kidney, etc. The coronary sinus carries the deoxygenated blood from the heart muscles itself. All these blood vessels pour deoxygenated blood into the right atrium. The right auricle is bigger than the left auricle because it has to hold more volume of the deoxygenated blood collected from all over the body. Superior vena cavaPulmonary arteryRight auricleAortaPulmonary arteryPulmonary veinsLeft auriclePulmonary valveAortic valveLeft ventricleSeptumCardiac musclePulmonary veinsTricuspid valveRight ventricleInferior vena cavaBicuspid/mitral valveInternal morphology or anatomy of the heart

122 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 123b) Left auricle It is the upper left chamber of the heart. Two pairs of pulmonary veins, one pair from each lung are connected to the left auricle. They carry purified or oxygenated blood.c) Right ventricleIt is the lower right chamber of the heart. Pulmonary artery arises from the right ventricle and is connected to the lungs. It carries deoxygenated blood from the heart to the lungs for purification. d) Left ventricleThe left ventricle is the lower left chamber of the heart. It is the main pumping chamber. The largest artery called aorta arises from the left ventricle and carries the oxygenated blood away from the heart to all parts of the body.Why are ventricles more muscular?Auricles have to pump blood only to the ventricles. But, ventricles have to pump blood to the lungs and other parts of the body at a high pressure. So, ventricles are more muscular than auricles.Why is the left ventricle more muscular than the right ventricle?The left ventricle has to pump blood to all parts of the body at longer distance while the right ventricle has to pump the blood to the lungs at a shorter distance. So, the left ventricle is more muscular than the right ventricle.FACTS WITH REASONDifferences between auricles and ventricles.S.N. Auricles S.N. Ventricles1. Auricles are the upper two chambers of the heart.1. Ventricles are the lower two chambers of the heart.2. They are relatively thin-walled. 2. They are relatively thick-walled.3. Auricles receive blood from inferior venacava, superior venacava, coronary sinus and pulmonary veins.3. Ventricles receive blood from the auricles. 4. Auricles open into ventricles. 4. Ventricles open into arteries. 5. Auricles pump blood to the to ventricles. 5. Ventricles pump blood to the lungs and all parts of the body.Heart and the four valves For one-way flow of the blood, there are four valves present inside the heart. A short description of these valves is given below.a) Tricuspid valveThe valve between the right auricle and right ventricle is called tricuspid valve (tricuspid means three flaps). It is also called right atrioventricular valve. When auricle contracts, tricuspid valve opens. At the same time the ventricle relaxes and blood flows from right

124 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 125auricle to the right ventricle. Similarly, when auricle relaxes, the tricuspid valve gets closed. At the same time, ventricle contracts and the blood flows from right ventricle to the pulmonary artery.b) Bicuspid valve or mitral valveThe valve present between left auricle and the left ventricle is called bicuspid valve. It is also called the mitral valve. It is the only valve that has two concentric flaps. It is also called left atrioventricular valve. When the left auricle contracts, bicuspid valve opens. At the same time, ventricle relaxes and blood flows from the left auricle to the left ventricle. Similarly, when right auricle relaxes, bicuspid valve gets closed. At the same time, ventricle contracts and the blood flows from the left ventricle to the aorta.c) Pulmonary valveThe valve present between pulmonary artery and right ventricle is known as pulmonary valve. It has three concentric flaps. This valve opens when the auricle relaxes and ventricle contracts. As a result, blood flows from right ventricle to the pulmonary artery. d) Aortic valveThe valve present between aorta and the left ventricle is known as the aortic valve.It also has three concentric flaps. This valve opens when auricle relaxes and ventricle contracts. As a result, blood flows from left ventricle to the aorta.The tricuspid and bicuspid valves are collectively called atrioventricular valves, as they lie between auricle and ventricle. Similarly, the pulmonary valve and aortic valve are called semilunar valves because they look like half-moon. There is a valve in aorta but no any valve in the pulmonary vein.The four valves in the heart maintain unidirectional flow of blood by preventing the backward flow. The atrioventricular valves allow unidirectional flow of blood from auricle to the ventricles. Similarly, the semilunar valves allow unidirectional flow of the blood from ventricles to the aorta and pulmonary artery. When ventricles contract, the atrioventricular valves close and the semilunar valves open. Similarly, when ventricles relax, the atrioventricular valves open and the semilunar valves close. In a normal healthy person, the flow of blood in the heart is always unidirectional. It flows from right auricle → right ventricle → pulmonary arteries → lungs → pulmonary veins →left auricle → left ventricle → aorta → body parts → right auricle. The blood circulation is maintained by the pumping action of the heart.Blood VesselsThe elastic tubes and pipes through which blood flows are called blood vessels. Blood vessels vary in shape, size, diameter and functions. Some blood vessels carry oxygenated blood while others carry deoxygenated blood. On the basis of structure and function, there are three types of blood vessels. They are:Tricuspic valvePosteriorAnteriorBicuspic valvePulmonary valveAortic valveRight side of heartLeft side of heartValves in the heart

124 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 125Arteries Arteries are thick-walled blood vessels that carry blood away from the heart. They start from the left ventricle of the heart as aorta i.e. the largest artery and then branch out. They carry oxygenated blood (except pulmonary artery which arises from right ventricle and carries deoxygenated blood). The wall of artery is made up of three layers. They are tunica interna (the innermost layer), tunica media (the middle layer, also the thickest) and the tunica externa(the outer layer). Arteries have thick wall to overcome high pressure. It is because the blood flowing in the arteries is directly pumped from the heart at a high pressure. They have a narrow lumen which maintains pressure to flow blood. No valves are present in the arteries because there is no chance of back flow of blood. Arteries branch out to form arterioles which further branch out to form capillaries. They are usually deep-seated in the body. It is because the loss of blood from the arteries is very dangerous during cuts and wounds as blood oozes out at a high pressure and clotting becomes difficult.Why are arteries thick walled?Arteries are thick walled to overcome the high pressure and high speed of the oxygenated blood which is directly pumped by the heart.Why do arteries have narrower lumen?Arteries have narrower lumen to increase the blood pressure. This sufficient blood pressure helps to transport blood to the different parts of the body. Pulmonary artery carries deoxygenated blood but is still called an artery, why?Pulmonary artery carries deoxygenated blood but is still called an artery because artery is a blood vessel that carries blood away from the heart. Pulmonary artery also carries the blood away from the heart to the lungs. Therefore, it is still called an artery even it carries deoxygenated blood.FACTS WITH REASONWhy do arteries have no valves?Arteries have no valves because valves prevent the backflow of the blood but there is no chance of back flow of blood in arteries as heart directly pumps the blood into the arteries at higher pressure.Blood loss from the arteries is dangerous. Give reason. Blood loss from the arteries is dangerous because: i) Arteries carry oxygenated blood and loss of oxygenated blood causes death of cells in the vital organs.ii) It is difficult for an artery to form blood clots after it is punctured.FACTS WITH REASONTunica externaTunica mediaTunica internaArteries

126 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 127Veins Veins are the thin-walled blood vessels that carry deoxygenated blood towards the heart (except pulmonary vein which carries oxygenated blood from lungs to the left auricle). Veins start from the different parts of the body as venules. These venules are formed by the union of many capillaries. All the veins of the body finally unite to form either superior venacava or inferior venacava. These large veins (venacava) pour blood into the right auricle. Like arteries, veins also have three layers in their walls, viz. tunica interna (innermost), tunica media (middle) and tunica externa (outer, thickest layer). They have a wider lumen than arteries through which deoxygenated blood flows easily at low speed and under low pressure. Veins have semilunar valves in them that allow one-way flow of blood. In veins, blood flows against gravity at low pressure. So, the valves at regular intervals prevent the back flow of the blood. Only three large veins of the body, viz. superior venacava, inferior venacava and the pulmonary veins do not have valves in them. Veins are superficial in position. They can be seen easily from outside. They cannot bear high pressure. Why are veins thin-walled?In veins, blood flows at low speed and under low pressure. Due to which extra thickness in the wall of the veins is not necessary.Veins have wider lumen, why?Veins have wider lumen to flow the large volume of the deoxygenated blood at low speed and under low pressure. Why do veins have valves at regular intervals?In veins, deoxygenated blood flows at low speed and under low pressure. From the lower parts of the body blood also flows against the gravity. In these conditions, there may be chance of back flow of the blood. Hence, to prevent the back flow of the blood, veins are provided with valves at regular intervals. FACTS WITH REASONWhy is blood seen as blue or purple from outside the veins?Veins are superficial. They have thin walls and transport deoxygenated blood. The wall of veins and deoxygenated blood absorb all the colours of light except blue. So, due to reflection of blue light, we see blood vessel blue or purple.Pulmonary vein carries oxygenated blood but it is still called a vein, why?Vein is a blood vessel that carries blood towards the heart. Pulmonary vein also carries blood towards the heart. Therefore, it is still called a vein even though it carries oxygenated blood.FACTS WITH REASONCapillariesCapillaries are hair-like, extremely narrow and thin-walled blood vessels. They are present everywhere in the body. Half of the capillaries transport oxygenated blood to the body while other half collect deoxygenated blood from there. They are the connection between arterioles and venules. They are microscopic with one cell layer thick. They are the actual site of the Tunica externaValveTunica mediaTunica internaVeins

126 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 127exchange of nutrients, toxic waste and gases (O2 and CO2). The wall of capillaries has only one layer. It is called tunica interna. Tunica externa and tunica media are absent. Presence of only one layer in the wall of capillaries supports them to reach up to the microscopic cellular level.Tunica internaArteryArteriole Capillary networkVenuleVeinCapillariesDifferences between arteries and veins.S.N. Arteries S.N. Veins1. Arteries carry blood away from the heart to the tissues. 1. Veins carry blood towards the heart from the tissues. 2. The blood in arteries flows at high pressure and under high speed.2. The blood in veins flows at low speed and under low pressure.3. They do not have valves (except in aorta and pulmonary artery).3. They have valves (except in superior venacava, inferior venacava and pulmonary vein).4. They usually carry oxygenated blood except pulmonary artery.4. They usually carry deoxygenated blood except pulmonary vein.5. They are located deep in the tissues. 5. They are located superficially in the tissues.6. They have narrow lumen. 6. They have wider lumen.Why are capillaries extremely thin-walled?Capillaries are extremely thin-walled because the thin wall allows the capillaries to exchange oxygen, carbon dioxide, nutrients, toxic waste, etc. in the cellular level. FACTS WITH REASONBlood circulation The heart of the vertebrates (except Pisces) follows the double circulation because the blood flows through the heart twice to flow the oxygenated blood once in the body. The deoxygenated blood from all over the body pours into the right auricle and then right ventricle of the heart. From right ventricle, the blood enters into the lungs. After oxygenation, the pure blood enters into the left auricle and then left ventricle to distribute throughout the body. A healthy heart pumps about 5-6 litres of blood every minute. The double circulation of the blood occurs through two ways.

128 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 129The blood circulation in human is called double circulation, why?In human blood circulatory system, the blood is transported to the heart twice: once from all parts of the body and second from the lungs. So, the blood circulation in human is called double circulation.FACTS WITH REASONPulmonary circulationThe type of circulation in which blood flows from right ventricle to the lungs and then to the left auricle is called pulmonary circulation. Pulmonary circulation starts from the right ventricle and pumps deoxygenated blood to the lungs through the pulmonary artery. In the lungs, the blood becomes oxygenated by exchanging carbon dioxide with oxygen. This process is called blood purification. After oxygenation, the lungs transport oxygenated blood through the pulmonary veins back to the left auricle.Systemic circulationThe flow of blood between the heart and different parts of the body is called systemic circulation. Systemic circulation starts from the left ventricle. When the left ventricle contracts, the oxygenated blood passes to the aorta, arteries, arterioles and finally to the capillaries. In the tissues, the capillaries exchange nutrition, oxygen, hormones, with metabolic wastes of the tissues like carbon dioxide, toxic materials, etc. Now, the blood becomes impure. This impure blood passes to the venules, veins, venacavae and finally to the right auricle of the heart. This is a complete systemic circulation. Blood group A blood group is a classification of blood, based on the presence or absence of antigens present in RBCs and antibodies in blood plasma. These antigens are designated by the English alphabets A and B and antibodies as a and b. Depending upon the presence and absence of these antigens and antibodies, four blood groups have been designated as A, B, AB and O. This system of blood grouping is called as ABO blood grouping system.Pulmonary circulationSystemic circulationPulmonary circulation and systemic circulationThe blood groups A, B and O were discovered by Karl Landsteiner in 1900 for which he got Nobel Prize in 1931.MEMORY TIPS

128 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 129FACTS WITH REASONSSome people used to die and some people used to survive after blood transfusion before the blood group was discovered.Some people used to die and some people used to survive after blood transfusion before the blood group was discovered because of the transfusion of the wrong blood group. Transfusion of wrong blood group is dangerous. The antigen of the opposite blood group will destroy the red blood cells and kills the patient. ACTIVITY 2Let’s survey the blood groups of our classmates. ABO blood grouping system i. If a person’s blood has antigen A in the RBC the person has blood group A. ii. If a person’s blood has antigen B in the RBC the person has blood group B. iii. If a person’s blood has antigens A and B in the RBC the person has blood group AB. iv. If a person’s blood has no antigen in the RBC the person have blood group O.Rh-Factor Rh-factor (Rhesus factor) is a protein (antigen) that is present on the surface of RBC. If Rh factor is present in a person’s blood, then blood is said to be Rh positive (Rh+) and if Rh factor is absent, then blood is said to be Rh negative (Rh–).Project WorkAsk to your elders and neighbour about their blood group. Make a list of their blood group and present in the class.FACTS WITH REASONSA person with blood group A should not transfuse blood group B. Immune system of person with blood group A will produce antibodies against blood group B antigens and destroy them resulting loss of blood cells. So, person with blood group A should not transfuse blood from person with blood group B.Determination of Blood group1. First of all, a finger is sterilized with a sterile cotton ball and pricked with a sterile blood lancet. 2. Three drops of blood are taken in different places on glass slides for A, B and Rh-Factor (D). Rh-Factor was first isolated from RBCs of Rhesus Monkey by Karl Landsteiner and Wiener in 1940.MEMORY TIPS

130 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 1313. The anti A serum is added in the drop of blood labelled A, anti B serum is added in the drop of blood labelled B and Anti D serum is added in the drop of blood labelled D, respectively. 4. The mixture of blood and antiserum is mixed properly with the help of a bamboo stick and allow resting for a few minutes to see agglutination (clumping). 5. If we see clumping in blood labelled A after putting anti-serum-A, then its blood group is A. 6. Similarly, if we see clumping in blood labelled B after putting anti-serum-B, then its blood group is B. 7. If we see clumping in both A and B, then the blood group is AB. 8. If we see no clumping in both A and B, then the blood group is O. 9. The clumping in sample D indicates the Rh+.10. If there is no clumping of a sample D, then the blood is Rh-.Importance of blood group in blood donationThe particular type of blood group has a particular antigen and particular antibody. If the wrong blood group is put in our body, it will be harmful to our health. The antigen and antibody present in our blood will fight against the newly injected blood. The blood starts to clot inside the veins and can even kill us. Therefore, blood groups should be tested before transfusion. ACTIVITY 3What is your blood group? If you do not know, ask your parents to take you hospital for a blood test. Blood Pressure (BP) The pressure exerted by blood on the walls of the arteries when the left ventricle contracts and relaxes is known as blood pressure. When the blood pumped by the left ventricle runs through the arteries, it creates a pressure against the wall of the arteries. This pressure is measured in the mercury column. Hence, the unit of blood pressure is millimetres of mercury (mmHg). It is represented by two numbers. The upper level number is called systolic blood pressure and the lower one is called diastolic blood pressure.

130 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 131Systolic blood pressureThe blood pressure felt in the arteries when the left ventricles contracts is called systolic blood pressure. The contraction of heart is also called as systole. In adults, systolic blood pressure ranges from 90-130 mm of Hg. The normal systolic blood pressure is considered 120 mm of Hg.Diastolic blood pressureThe blood pressure felt on arteries when the left ventricle relaxes is called diastolic pressure.The relaxation of heart is called diastole. In adults, the diastolic blood pressure ranges between 60-90 mmHg. The normal diastolic blood pressure is considered 80 mmHg. The blood pressure of a person changes with the factors like age, sex, time of the day, stress, exercise, work, emotions, disease, fear, etc. Sphygmomanometer is the device that measures blood pressure. A trained person can measure the correct blood pressure by using such an analog sphygmomanometer. But a digital sphygmomanometer is easy to operate without training. It can be used in noisy environments too.If the blood pressure increases above the value 140/90 mmHg, it is called high blood pressure. Similarly, if it drops below 90/60 mm of Hg, it is called low blood pressure.High blood pressure (Hypertension) High blood pressure is a condition in which the heart pumps blood at high pressure against the wall of arteries. High blood pressure increases the risk of heart attack, kidney damage, cardiovascular stroke, nerve damage around blood vessels, etc. High blood pressure cannot be treated fully but with the change in life style, it can be kept in control. It is necessary to keep the blood pressure under control to avoid the risk of death by heart attack, brain haemorrhage, kidney damage, etc. Symptoms of high blood pressure The blood pressure of a person will be greater than 140/90 mmHg if s/he is suffering from high blood pressure. The disease is also called hypertension. The patient with high blood pressure has difficulty falling asleep. They are usually stressed and annoyed and get angry faster. Other symptoms are anxiety, headache, sweating, red face, nosebleeds etc. Causes of high blood pressure Most of the causes of high blood pressure are idiopathic (not known). But, there are some causes which increase the chances of hypertension. They are:i. Ageing (age more than 40 years)ii. Over weightAnalog sphygmomanometer Digital sphygmomanometerIf the blood pressure of a person is 120/80 mm of Hg, it means that the systolic blood pressure is 120 mm of Hg and the diastolic pressure is 80 mm of Hg. These values of blood pressure are within the normal limit.MEMORY TIPS

132 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 133iii. Family history of high blood pressure (heredity)iv. Excessive salt intake in dietv. Excessive smoking and drinking alcohol vi. Lack of physical exercise vii. Kidney, thyroid and adrenal diseases viii. Diabetes ix. Women using birth control pillsx. Stressful livingxi. PregnancyPreventive and control measures of high blood pressure High blood pressure cannot be fully treated. But, with some changes in lifestyle, the blood pressure can be kept under safer limit. Some of the ways to reduce the risk of high blood pressure are:i. We should reduce weight if our weight is above the limit.ii. We should do regular physical exercises. iii. We should eat low salt and low sugar.iv. We should avoid smoking and drinking alcohol.v. We should eat balanced diet.vi. We should avoid fatty, oily, and spicy foods. vii. We should reduce stress and avoid stressful living. viii. We should avoid the consumption of fatty red meat.ix. We should monitor blood pressure regularly.Heart BeatIf we hold a stethoscope close to the chest, we will hear the repetitive lubb-dup sound of the heart. It goes somewhat this way: lubb-dub—lubb-dub—lubb-dub…. The lubb sound (first heart sound, S1) represents the contraction of the ventricles and the relaxation of the auricles. Likewise, the dub sound (second heart sound, S2) indicates the relaxation of the ventricles and contraction of the auricles. But, the heart sounds are actually produced by the closing of the heart valves. The closing of the mitral and the tricuspid valves produces the first heart sound (lubb sound S1), whereas the closing of the pulmonary and the aortic valves produces the second heart sound (dub sound S2).A heart beat is a continuous rhythmic beat throughout the life which is produced due to complete contraction and relaxation of the heart muscle. A normal healthy person has 60-100 temporary arteryfacial arterycarotid arteryfemoral arteryBrachial arteryRadial arteryPopliteal arteryPosterior tibial artery dorsalis pedis arteryMajor superficial pulse points

132 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 133times heart beats in one minute. If the heart of a person beats less than 60 times per minute, it is called a slow heart. It is also called bradycardia. If the heart of the person beats more than 100 times per minute, it is called a fast heart. It is also called tachycardia.Arterial pulseThe repetitive jerk felt at the major arteries of the body due to the pumping action of the heart is known as the arterial pulse. In a normal healthy person, the arterial pulse is equal to the heart beat i.e. 60-100 times per minute. The major arteries where the pulse can be felt are radial artery (wrist), common carotid artery (neck), temporal artery (temporal lobe of head), etc.DiabetesWe need energy to work. The required energy is derived from the metabolism of food that we eat. Our food mainly contains carbohydrates, proteins and fats. They are broken down into simpler molecules like glucose and amino acids. Most of our energy is derived from glucose. Except brain, liver and testes, most of the cells require a hormone called insulin for the better use of glucose in the body. Insulin is a hormone secreted by pancreas that helps in glucose utilization. Thus, insulin helps to remove excess glucose present in the blood by utilizing in the cells. Lack of insulin causes high level of glucose in the blood. The condition of high level of glucose in the blood is called hyperglycaemia. If the function of insulin is affected or the cells of pancreas are damaged, the ability of the body to remove excess glucose from the blood is reduced. This condition is called diabetes. Thus, the condition in which body becomes unable to maintain normal glucose level due to the lack of insulin is called diabetes mellitus. It is also called sugar disease.A random glucose test can be done at home too by a portable device called glucometer.The normal range of glucose in blood for a healthy person is from 80-110 mg/dl (milligrams/decilitre).MEMORY TIPSCauses of diabetes i. Diabetes is caused due to the damage of insulin producing cells of pancreas.ii. It is caused due to insulin resistance.iii. Obesity and inactive lifestyle may cause diabetes.iv. Unbalanced diet with more fats and carbohydrates may cause diabetes. v. Aging is also responsible for diabetes.vi. Heredity also may cause diabetes. Symptoms of diabetes i. Sugar deposits on the retina and vision will be blurred.ii. Sugar deposit on wounds. Bacteria grow there so wounds heal slowly.iii. A sugar patient has excessive hunger and thrust. iv. Muscle spasms, dizziness, numb hands and numb legs v. Sometimes sugar patients can be unconscious vi. Frequent urination

134 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 135Preventive measures of diabetesDiabetes cannot be cured completely, but can be effectively controlled. With an appropriate change in lifestyle, one can prevent it (except if it is genetic). Some preventive measures for diabetes are a morning walk, regular exercise, drinking sufficient water, an active lifestyle, avoiding stress and eating fresh and healthy food etc. A balanced diet, correct body mass index and morning walk help reduce sugar in the blood.Diabetes may be caused by inactive lifestyle, why?Due to the lack of exercise, the extra glucose is stored in the body and is not used up. This stored glucose in the body increases the body weight and thus the level of glucose in the blood may not be maintained properly. It finally leads to diabetes.People should monitor their blood pressure regularly, why?People should monitor their blood pressure regularly to detect the increase or decrease in the pressure beyond normal values. Both high blood pressure and low blood pressure are dangerous. If we monitor blood pressure regularly, we can prevent various cardiovascular diseases. We should eat a lot of fruits and vegetables, why?We should eat a lot of fruits and vegetables because they provide us vitamins and minerals which help to fight against diseases, prevent high blood pressure, diabetes, etc. and remove toxic substances from the body.FACTS WITH REASONGout or Uric acid Uric acid is a compound which is produced by the breakdown of an organic compound called purine. Purines are nitrogenous compounds that help to make DNA, RNA and proteins in the human body. The sources of purines are liver, kidneys and brains of animals, beans, alcoholic beverages, mushroom, sea foods, red meat, tomatoes, eggs, etc. Uric acid helps to prevent heart attack by removing plaque in arteries. It prevents coronary blockage. It is believed that uric acid is an antioxidant which helps to remove toxic materials from our body and also protects the inner walls of the blood vessels. Foods rich in purines may cause uric acid. The high concentration of uric acid is harmful to our body. The normal level of uric acid in blood is 3.4-7.2 mg/dL (milligrams/decilitre). The condition in which there is excess of uric acid in the body is called hyperuricemia. Generally, the high level of uric acid in blood is prevented due to its excretion by the kidneys through urine. If kidneys fail to excrete enough uric acid, it gets precipitated and deposited in the soft tissues and large joints of the body. This causes gout. The disease caused by the deposition of uric crystals in the soft spongy bone tissues at joints is called gout.Project WorkAsk to your elders and neighbours about the condition of their blood pressure and uric acid. Make a list and present in the class.Purine is broken down into uric acid by liver and intestinal mucosa to produce uric acid.MEMORY TIPS

134 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 135Causes of uric acid (Gout)Causes of increasing uric acid in the body are eating a more protein-based diet such as red meat, legumes and seafood. Drinking very little water per day. Kidney failure can also increase uric acid. Lack of exercise and obesity increases the probability of uric acid. Symptoms and effects of uric acid (Gout)i. Gout, pain in joints ii. Red swollen skin with a burning sensation iii. A kidney stone, deep muscle pain etc. iv. Difficulty walking due to joint pain v. Painful joints when cereals or red meat is eaten Preventive and control measures of uric acid (gout)i. Drink sufficient water. ii. Eat food that contains baking soda.iii. Do not eat greasy food and red meat.iv. Reduce consumption of seafood.v. Consume fewer amounts of cereals.vi. Eat cherries and baking soda every day.vii. It is necessary to reduce obesity. A patient with uric acid should eat the cherry.A patient with uric acid should eat cherry because it contains an antioxidant called anthocyanin. Anthocyanin helps to reduce uric acid in the blood. FACTS WITH REASONHeart attackThe heart is an organ responsible for blood pumping. It is made of cardiac tissue. It needs energy to survive, produce new cells, repair and so on. Therefore, the tissue of the heart also needs a continuous pure blood supply. The coronary artery supplies pure blood to the tissues of the heart. The coronary artery branches into many arterioles and reaches every corner of the heart. The pure blood supplies oxygen and nutrients to the cells of the heart. The metabolic waste produced by the cardiac tissues is collected by venules and given to the coronary sinus. The coronary sinus removes impure blood and waste from the tissues of the heart. Under unfavourable situations such as old age, smoking, diabetes, plaque, obesity, inactive life, high blood pressure, lack of sleep etc. The blood vessels can get narrower. The plaque can block the coronary artery. As a result, the flow of blood to the heart or a certain part of the heart stops, which is called a heart attack. The condition when the tissues of the heart do not receive sufficient pure blood is called a heart attack. It is also called myocardial infarction. The heart attack happens over time. Due to lifestyle, spicy food etc, the branches of the coronary artery keep being blocked over time without even any major symptoms. So, we should keep checking our hearts from time to time. If the heart stops beating due to a heart attack, it is called cardiac arrest. Swollen and inflamed jointuric acid crystalsgoutHeart attack from the use of cocaine is one of the most common causes of sudden death in young people.MEMORY TIPS

136 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 137A healthy lifestyle can reduce the probability of heart attack. A balanced diet helps to reduce cholesterol and triglycerides, physical activities help to reduce obesity, enough sleep reduces stress and lowers blood pressure and avoiding sugary foods helps to avoid diabetes. As a result, the chance of a heart attack will decrease. Hence, a healthy lifestyle can reduce the probability of a heart attack. FACTS WITH REASONSACTIVITY 4Explain the risks and preventive measures of heart attack to your parents. Symptoms of a heart attacki. pain in the chest, pain in chest slowly grows to shoulder ii. pain in the lower jaw and stomach iii. cold sweat, restlessness and headache iv. headache, dizziness and short breath v. regular discomfort in the chest many hours or weeks before the heart attack. Causes and risk of heart attack High cholesterol, hypertension, bad cholesterol and sedentary life are major causes of heart attack. Age, gender and family history also increase the risk of heart attack. i. Diabetes: Diabetes can damage blood vessels. Fats deposit in damaged blood vessels and reduce the flow of blood into the heart. So, consumption of unhealthy food, sugary foods, lack of balanced diet etc can lead to diabetes which leads to heart attack.ii. Hypertension: High blood pressure makes blood vessels narrower and ventricles thicker. As a result, less blood flow in the heart and cause heart attack. So, any activities such as smoking, drinking alcohol, stress, skipping sleep, obesity, salty foods and lack of exercise can cause heart attack because they increase blood pressure. iii. High cholesterol and triglycerides: Deposition of cholesterol and triglycerides in blood vessels makes them narrow. They form plaque, block coronary arteries and cause heart attacks. So, any activities that increase cholesterol are the cause of heart attack. For example, consumption of fatty food, oily food, fried food, alcohol etc. iv. Sedentary life: An inactive life, lack of exercise and lack of a balanced diet can cause high blood pressure, high bad cholesterol, high blood sugar and faster ageing. These conditions damage blood vessels, make them narrow, block coronary arteries and cause heart attacks.v. AgeAge and gender also affect the chances of heart attack. Males aged 45 years and above and females 55 years and above have a higher chance of heart attack than younger people.

136 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 137vi. Family background (heredity)The children of the family who have a history of heart attacks among family members also have a greater chance of heart attack than those who have no history of heart attack. Preventive measures i. Do regular physical exercise. Reduce obesity. ii. Eat a balanced diet. Avoid junk food, fatty food and fried foods.iii. Sleep enough, take rest and avoid stress.iv. Reduce sugary foods, avoid diabetes etc. v. We should be extra careful about lifestyle, food habits and fitness if there is a family history of heart attack or if we are older. Morning walks, swimming and cycling can help reduce the probability of heart attack.Morning walks, swimming and cycling can help reduce the probability of heart attack because they reduce stress, burn fat, keep us fit and reduce obesity. FACTS WITH REASONSACTIVITY 5Practise following the preventive measures for heart attack every day. Live a healthy life. Diagnosis and curative measures of heart attack Diagnosis of a heart attack is the activity in which doctors try to find out if a person has a heart attack or not. They test the heart, heartbeat, heart rate, blood, pulse and blood pressure very carefully to detect heart attacks. Heart attack is diagnosed by Electrocardiogram, echo, angiography, CT coronary angiogram, MRI and blood test. Doctors can use it to find out the cause of pain. Angiography is a popular method for the diagnosis of a heart attack. It is a type of fluoroscopy. The objective of this process is to locate blockage. So, the principle is to supply dye mixed blood into the heart and take x-ray images. If some coronary artery cannot pass dye-mixed blood from some point, it must be a blockage. First of all, the suspect patient is laid in the bed. The patient should drink tea or water and rest. Then the doctors will make a small cut at the arms. The cut will also be made on the blood vessels. Then a thin tube called a catheter is inserted into the blood vessels. Then a contrast medium is mixed in the blood. Contrast medium is a special dye. Usually, X-rays cannot take images of blood vessels because they do not reflect light that much. So, it is compulsory to mix dye. After a few minutes, the dye-mixed blood will reach into the heart. Then the doctors will use an x-ray machine to make multiple images of the heart continuously. Real-time images will be made on the computer. These X-ray images formed during angiography are called angiograms. Doctors view angiograms to find the blockage. An angiogram is very important in locating plaques that have blocked coronary arteries. It also helps to find narrow arteries. This information can be used to find out about heart attack, plan treatment and perform angioplasty to treat heart attack and save life. When the heart attack is diagnosed, curative measures should be started. ‘Coronary angioplasty MEMORY TIPSConsumption of tobacco and illegal drugs are also the causes of heart attacks.

138 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 139and stenting’ and Coronary artery bypass surgery are two popular curative measures for heart attack. Coronary angioplasty and stenting are preferred if fewer coronary arteries are blocked. Coronary artery bypass surgery is preferred during an emergency when multiple coronary arteries are blocked and the heart is about to stop. If both curative measures of heart attack are not available in the hospital, the doctors use blood thinning medicines such as aspirin and transfer patients to required hospitals. Oxygen is supplied continuously to the patient and kept on the ventilator. Coronary angioplasty and stenting The objective of coronary angioplasty and stenting is to treat heart attack by widening or opening the blocked coronary artery. It is also called percutaneous coronary intervention (PCI). The process of widening or opening the blocked coronary artery is called angioplasty. The angiography process is used to detect blockage. They pass dye into the blood which goes to the heart and they take X-ray images to locate blockage. When the blockage is detected by looking at an angiogram, the angioplasty technique is used to open the blockage. Particularly balloon angioplasty is popular. A cardiologist, a heart specialist, uses a flexible tube called a catheter to reach the blockage. The catheter is passed into the blood vessels through a minor cut in the arms. Then it is guided up to the blockage. The stent is transported up to the blockage. A stent is a metallic tube, which is used to open the blockage in blocked arteries. Stenting is the process of opening a blockage with the help of a stent. Here a mesh stent along with a balloon is passed into the blockage. The balloon is filled with air. Then the balloon grows bigger and the stent relaxes. The relaxed stent open the blockage. The stent is left at the blockage and the balloon is removed. It keeps the artery open and restarts the flow of pure blood into the heart. The stent is also coated with medicine which helps to keep blockage open. It prevents the heart from stopping (cardiac arrest). Aspirin is given to the patient of a heart attack in case tools for angioplasty are not available.Aspirin is given to the patient of a heart attack in case tools for angioplasty are not available because aspirin is a blood thinner. It makes the blood thin, so that it can pass even through the narrow artery and blockages. It helps to reduce chance of stopping of heart. FACTS WITH REASONSCoronary artery bypass surgery: The process of using a saphenous vein to create a new path to flow pure blood across the blockage into the heart is called coronary artery bypass surgery. Heart bypass Stent is a small metal mesh tube.MEMORY TIPSFigure: AngiographyThe new alternate path supplies oxygenated blood and nutrients to the tissues of the heart and prevents cardiac arrest after open heart surgery.MEMORY TIPS

138 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 139surgery is suggested for patients when their multiple coronary arteries are blocked and they are about to die. The angiography process is used to detect blockage. They pass dye into the blood which goes to the heart and they take X-ray images to locate blockage. When the blockage is detected by looking at an angiogram, doctors perform major surgery to create alternative paths for pure blood. The procedure of heart bypass surgery: The concept of open-heart surgery is to make an alternate path around the blockage for the flow of pure blood into the heart tissue. It is a major surgery where the sternum is cut and the chest is opened to find the heart. Then the doctors harvest a healthy blood vessel from the chest or leg. They use this graft blood vessel to make an alternate path for pure blood. They connect one end of the graft at the aorta and another end into the tissue of the heart. This will restart blood flow into the heart and prevent heart attack and cardiac arrest. Angiography is a very important technology. Angiography is a very important technology because an X-ray machine is used continuously over the chest of a patient to obtain a clear picture of the blood vessels of a patient in the monitor. It helps to detect heart attacks and suggest treatment. FACTS WITH REASONSACTIVITY 6Make a 3-D model to explain coronary artery bypass surgery.Cardiac rehabilitationWhen someone survives a heart attack. They must be very careful and live a healthy life, eat a balanced diet and do regular physical exercises. Visit the hospital for follow-up and consume medicine as directed by doctors. Figure: Coronary bypass surgery

140 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 141HOT SKILL HIGHER ORDER THINKING SKILL1. The wall of the ventricle is highly muscular or thicker than the wall of the auricle.Auricles do not need to push blood far. So, auricles do not need to have thicker walls. But the ventricles must produce enough force to push the blood farther by contracting. So, it must be muscular and thicker to produce sufficient force. 2. Mr. Anurema once survived a heart attack. Doctors performed balloon angiography on him to save his life. Mention the lifestyle should he live from now onwards.Mr. Anurema once survived a heart attack because doctors performed angiography on him. Therefore, he must practice cardiac rehabilitation and live a healthy life. For example:i. He should avoid drinking alcohol.ii. He should not stress over small issues. He should learn ways to handle stress. iii. He should quit smoking to reduce his blood pressure. iv. He should eat a healthy balanced diet. Especially low on fat, salt and spices.v. He should consume more vegetables, grains and low-fat dairy products. vi. He should do physical exercises regularly.3. Write the main function of blood.The main functions of the blood are regulation, transportation and protection.i. Transportation: Blood transports nutrients, oxygen, enzymes, medicines, drugs, hormones, waste etc. ii. Regulation: Blood regulates the body temperature, water level, hormone level etc. iii. Protection: Blood makes an immunity system and protects the body from different kinds of diseases. They also heal wounds and start blood clots.4. While Toshima was walking on the road, she saw an old man suffering from chest pain. She rushed him to the hospital. The initial examination suggested that he might have a heart problem. Which test would be appropriate to identify his heart condition? Explain with reason. Since Toshima found an old man who had chest pain and an initial examination in the hospital suggested a heart problem, an electrocardiogram (ECG) and a blood test would be appropriate to identify his heart problem. It helps to find out blood pressure and pulse. Doctors can use it to find out the cause of pain. Additionally, echo, angiography, angiogram and MRI are also used to test for heart problems. They help to see if there are any blockages in coronary arteries. 5. Sambriddhi gets tired even after walking a short distance and also finds it difficult to breathe. What is the reason for this? Anaemia could be the reason due to which is Sambriddhi gets tired after a short walk and has difficulty breathing. 6. Describe the main parts of the human circulatory system.The human circulatory system is the organ system in the human body which is responsible for the distribution of blood all over the body to supply the necessary materials to cells and also to collect unwanted materials from the body and send them to the excretory system. The heart, blood and blood vessels are three main organs of the human blood circulatory system. Heart: A heart is a small triangular blood-pumping muscular organ. It weighs about 300 grams. It has four chambers. The upper two chambers are called auricles. They have a thin wall. They collect blood. The lower, larger and thicker chambers are called ventricles. They push blood away from the heart.

140 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 141Blood:Blood is a thick, red viscous liquid in the body. 55% of blood is plasma. Plasma is a paleyellow liquid that helps in blood clotting, regulation of temperature and regulating water, hormones and temperature. The 45% of blood is blood cells. The red blood cells help in the transportation of oxygen and carbon dioxide. The white blood cells help to make an immunity system. The platelets are responsible for blood cuts in wounds. Blood vessels:Blood vessels are muscular elastic tubes that make the path for blood circulation. The arteries are thickwalled, valveless and deep-seated blood vessels. They take away blood from the ventricles of the heart. The veins are thin-walled, valve-containing and superficial blood vessels. They take blood toward the auricles of the heart. Capillaries are very thin blood vessels. They help in the exchange of oxygen and nutrients with carbon dioxide and uric acid from cells. In conclusion, the heart, the blood and the blood vessels work together for a common function and make a human blood circulatory system. 7. Study the given table and answer the following questions.Person Injury The flow of blood from the injured part X Superficial Continuous bleeding, first aid don’t stop bleeding Y Deep Bleeding with high pressure, it was stopped by general treatment Z Superficial Bleeding for a while and stopped a. Which person suffers from haemophilia?Ans: Person X is suffering from haemophilia.b. In which person is the artery injured?Ans: The artery is injured in person Y. c. Which injury, Y or Z is more dangerous? Give a reason.Ans: The injury of person Y is more dangerous because the injury is deep and blood is flowing in high pressure from the artery. So, it will be very difficult to stop compared to the injury of person Z. 8. Even though WBC is responsible for producing antibodies, fighting germs and building an immunity system, excessive WBC count is fatal for health. How?Even though WBC is responsible for making the immune system, excessive WBC is fatal for health because it starts to kill red blood cells. It can cause dizziness, fatigue and vomiting. 9. Look at the following blood vessels shown in the table below and answer the following questions. Pure blood Impure blood Contains valve A CDoes not contain valves B Di. Which one is the pulmonary artery?C is the pulmonary artery in the above table. ii. Which one is the pulmonary vein? B is the pulmonary vein in the above table. 10. A person has a light headache, sweating, anxiety and a blood pressure of 145/95. Which disease do these symptoms refer to? How can one minimize or control his/her symptoms without medications? Modern lifestyles are responsible for diabetes, uric acid and blood pressure, etc. Justify the statement. The above symptoms refer to high blood pressure. One can minimize or control his/her symptoms by changing his/her lifestyle. Taking a diet with low fats, carbohydrates, proteins, less salt, daily exercise,

142 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 143stress control, etc. are some of the ways to control high blood pressure. If these continuous efforts do not lower blood pressure, one should follow medications. Nowadays, facilities are easily accessible. People do very less physical work. They do maximum work by using different kinds of machines. They want to live luxurious life using modern equipment. Not only these, but farmers also became more commercial. They use different kinds of chemical fertilizers, insecticides, pesticides, etc. to increase the production of crops, vegetables and fruits. Consumption of these food products and a passive lifestyle are responsible for diabetes, uric acid and blood pressure. 4 STEPS EXERCISE EXERCISESTEP11. Multiple Choice Questions a. What is not the function of plasma?i. coagulation of blood ii. immunity against diseases iii. transportation of hormones iv. absorption of oxygen from lungs b. What is phagocytosis?i. process of producing antibodies ii. process of producing heparin iii. process of engulfing germs iv. process of coagulating blood c. Look at the following blood vessels. Which one is the pulmonary artery? Pure blood Impure blood Contains valve A CDoes not contain valves B Di. A ii. Biii. C iv. D d. The flow of the blood inside the heart is shown in the order below. Which one is in the correct order?i. right auricle → right ventricle → lungs → left auricle → left ventricle ii. left auricle → left ventricle → lungs → right auricle → right ventricle iii. left auricle → right ventricle → lungs → right auricle → left ventricle iv. right auricle → left ventricle → lungs → left auricle → right ventricle e. How does blood flow in double circulation?i. heart → body → heart → lungs → body ii. lungs → heart → body → lungs → body iii. heart → body → lungs → body → heart iv. body → heart → lungs → heart → body f. What is the function of the pericardium? i. protect the heart, lubricate the heart, keep the heart in place ii. cover the heart, prevent infection, transfer blood iii. prevent bacteria, keep the heart warm, reduce friction iv. keep heart moist, absorb mechanical shock, supply blood

142 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 143g. Which type of blood circulation is shown in the concept map below?Coronaryarterycardiac tissueCoronarysinusi. pulmonic circulation ii. cardiac arrest iii. systemic circulation iv. open circulation h. Study the conversation between these friends and select the best comment. Radha: Let’s go for a morning walk. It will help us avoid stress and remove belly fat. Binita: Let’s go! I have heard that it also reduces the risk of heart attack. Bhawana: It also increases uric acid in the blood. i. Radha and Binita have the wrong information. Bhawana has the correct information.ii. Bhawan has the wrong information. Radha and Binita have the correct information.iii. Radha is correct. Binita and Bhawana made wrong statements. iv. Binita made the correct statement. Radha and Bhawana made wrong statements. i. A blood sample of Mr. Kailash is tested using various serums and the result is given below. What is his blood type?Antigen A Antigen B Antigen DBlood clot Not seen Not seen Not seen i. A negative ii. B negative iii. AB negative iv. O negative j. What is shown in the diagram?i. coronary heart bypass surgery ii. angioplasty iii. uric acid iv. vein and the valve a. iv b. iii c. iii d. i e. iv f. i g. iii h. ii i. iv j. ii Ans of MCQSTEP22. Very short questions a. How thrombus cause a heart attack? b. Eating a lot of cherries is beneficial to health. Give reason. c. Which diseases is the patient suffering from?Blood pressure Systolic pressure Diastolic pressure Magnitude 150 mmHg 100 mmHgd. Which one of the following, shown in the diagram, is the soldier of the body? e. What happens to the blood pressure when the left ventricles relax?

144 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 145f. Write the name of granular WBCs.g. No antigen is present in the blood. What is the type of blood?h. Name the largest artery and vein in the human body. STEP33. Short questions a. Write any two differences between RBC and WBC. b. A person is tired and weak with cold hands and feet. S/he has pale skin and shortness of breath. What might he be suffering from?c. Blood group must be identified before blood transfusion. Discuss.d. In the given figure A and B which blood vessel carries blood from the lungs to the heart and which has high blood pressure?e. Ezikel was diagnosed with a kidney stone, pain in joints and red swollen skin. What disease might he be suffering from? Write its causes and preventive measures.f. If some coronary arteries are blocked at once, a person could die from a heart attack. Doctors use a stent to open the blockage. The stent is left there permanently. Why?g. ‘There is a high risk of diabetes, uric acid and blood pressure in people with an inactive lifestyle.’ Justify the statement.h. A patient has problems with frequent urination, intense hunger and thirst, dizziness, wounds not healing quickly, and so on. What disease is the person suffering from? What do you suggest to prevent this disease?STEP34. Long questions a. Study the story and answer the following questions:[Yogesh was smoking, drinking beer, and eating roasted red meat with his friends after his office work. Today he felt discomfort at the centre of his chest which felt like uncomfortable pressure, fullness and squeezing. Shyam suggested Yogesh to eat some gastric tablets. Slowly, Yogesh reached home and went to bed. But he had trouble sleeping, cold sweat and short breath. His daughter Arya, realised that it could be a heart attack and rushed him to hospital. Doctors confirmed that it was a heart attack. Doctors performed angioplasty to save his life.]What led Yogesh to suffer from this disease? Since he has survived a heart attack, how should he live his life from now onward?

144 PHySiological StRuctuRe and life PRoceS S Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 145Copy the table and circle either yes or no in the given table. Doctors used angioplasty because the pulmonary artery was blocked. Yes / No Since he has survived a heart attack, he should do regular exercise and quit smoking.Yes / No b. The following results were obtained when the blood samples of four people were tested.i. A–RBC count too low ii. B–WBC count too high iii. C–Platelet count too low iv. D–Concentration of sugar too highAnswer the following questions based on the above information. i. The person with which blood sample needs to avoid injury and Why? ii. The person with which blood sample should avoid heavy work and why?iii. The person with which blood sample needs to take antibiotics and Why?iv. The person with which blood sample could have a problematic kidney condition, why?c. In the diagram, P, Q, R and S are four chambers of the heart X and Y are organs or groups of organs K, L, M and N are showing blood vessels. Answer the questions based on the diagram.i. In which blood vessels do pure blood flow? ii. Write any two differences between S and Q.iii. What is the purpose of the flow of blood in organ X? iv. Why do blood vessels have elastic walls?d. Study the diagram given below and answer the following questions. i. Which procedure to treat a heart attack is shown in the diagram?ii. What is the objective of blood vessel A?e. Draw the diagram of the internal structure of the heart to show the location of each valve and four chambers. ♦♦♦

146 natuRe and enviRonment Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Approved by the Curriculum Development Centre, Sanothimi, Bhaktapur Modern Concept Science & Technology - 10 147Key terms and terminologies of the unit1. Climate : The atmospheric condition of a wide region that remains almost the same for at least 30 years is called a climate.2. Climate change : The process in which the atmospheric condition of a huge area differs gradually over a very long time due to natural activity or human activities is called climate change.3. Weather : The change in the day-to-day condition of the atmosphere is called weather. 4. Fossil fuel : The fuel obtained by burning fossils such as coal and petroleum is called fossil fuel. Coal, petrol, diesel and LPG gas are fossil fuels. They are major sources of carbon dioxide gas. 5. Greenhouse gases : The gases that can trap heat energy and significantly change the temperature of the atmosphere are called greenhouse gases. For example, carbon dioxide, water vapour, methane etc. 6. Greenhouse effect : The process by which greenhouse gases such as carbon dioxide, water vapour, etc. can trap solar energy and increase the temperature of the earth is called the greenhouse effect. 7. Global warming : The process in which the over-greenhouse effect increases the temperature of the earth gradually is called global warming. 8. Biodiversity : The presence of various breeds and species of lifeforms connected by the food chain in a particular place is called the biodiversity of that place.9. Endangered species or rare species : The species whose population has declined significantly and are too few in a place, in a country or on the earth are called endangered or rare species. Sequence of Curriculum Issued by CDC Concept of climate change: cause, effects and control measures Different kinds of endangered animals in Nepal and their conservation Importance, identification and uses of medicinal plantsUNITNature and Environment6Estimated teaching period Theory Practical5 2Jyoti Bhandari, a Nepali researcher, has made remarkable strides in the study of medicinal plants and their utilization in traditional medicine. Armed with a PhD from Osaka University, Japan, Bhandari's research focuses on unravelling the chemical composition and pharmacological properties of these plants. Their efforts serve to bridge the gap between traditional and modern medicine, providing invaluable insights that enrich both domains. Jyoti BhandariAbout the Nepalese Scientist