Modern Concept Science and Technology Book 5 101 Key terms and terminologies of the unit 1. Vertebrates : Those animals which have a backbone in their body are called vertebrates. 2. Pisces : The class Pisces includes different types of fishes which breathe through gills and have fins for swimming. 3. Amphibia : The class amphibian includes those vertebrates which can live both in water and on the land. 4. External fertilization : In external fertilization, the fusion of sperm and ovum takes place out of female body in water. 5. Reptilia : The class Reptilian includes cold-blooded, crawling animals. 6. Mammalia : The class Mammalian includes the animals which have mammary glands in the females and give direct birth to their young ones. 7. Internal fertilization : In internal fertilization, the fusion of sperm and ovum takes place inside the female body. 8. Oviparous : The animals which lay eggs are called oviparous animals. 9. Viviparous : The animals which give direct birth to their young ones are called viviparous animals. Sequence of Curriculum Issued by CDC Features of vertebrates (pisces, amphibians, reptiles, aves and mammals) Examples of class pisces, amphibians, reptiles, aves and mammals UNIT Vertebrates 4.1 Estimated teaching period Theory Practical 7 3 Carolus Linnaeus, was a Swedish botanist and explorer. He was born in 1707 and died in 1778. He was the first person to classify the living organisms in scientific way. He developed principles for defining genera and species of organisms and to create a uniform system for naming them. His naming of organisms using genus and species is known as binomial nomenclature. Carolus Linnaeus About the Scientist
102 Modern Concept Science and Technology Book 5 Introduction We can see different types of animals in our surroundings. Among them some are small and others are big, some have backbone and others do not. Animals like fish, frog, tortoise, birds, dog, human, etc. have the backbone. So, they are called vertebrates. Thus, those animals which have a backbone in their body are called vertebrates. Most of the vertebrates live on land but some vertebrates live in water. They have well-developed body organs and body systems, such as respiratory system, digestive system, reproductive system, circulatory system, nervous system, etc. On the basis of structure and development, vertebrates are divided into five different classes. They are: i. Pisces ii. Amphibia iii. Reptilia iv. Aves v. Mammalia I. Pisces The class Pisces includes different types of fishes which breathe through gills and have fins for swimming. They are aquatic vertebrates. Their body is divided into head, trunk and tail. These animals have boat-shaped body. They have fins for swimming and tail for changing the direction. Their body is covered by waxy scales that save them from decaying in water. They are oviparous and cold-blooded animals. For example, salmon, shark, sea horse, eel, carp, ray fish, etc. Shark Carp Ray fish Fig : Some fishes Sea-horse Pisces have two chambers in their heart MEMORY TIPS
Modern Concept Science and Technology Book 5 103 II. Amphibia The class Amphibia includes those vertebrates which can live both in water and on the land. Their body is divided into head and trunk. They have strong limbs for swimming in water and jumping on the land. Their hind limbs are longer and stronger than their fore limbs. They have sticky tongue to catch the prey. They have soft and moist skin with glands. They breathe through gills in water and through lungs on the land. They are oviparous and cold-blooded animals. Some examples of the class Amphibia are frog, salamander, toad, etc. Frog Toad Salamandar Fig : Some amphibians III. Reptilia The class Reptilia includes cold-blooded, crawling animals. The body of reptiles is divided into head, neck, trunk and tail. Most of the reptiles live on land while some live in water. They have two pairs of limbs for locomotion except in snakes. They have dry, rough and scaly skin. They breathe through lungs. They are oviparous animals. Some examples of reptiles are snake, crocodile, turtle, etc. Lizard Snake Crocodile Fig : Some reptiles Pisces and Amphibia show external fertilization. It means that fusion of sperm and ovum takes place out of female body in water. MEMORY TIPS Amphibia and Reptiles have three chambers in their heart. MEMORY TIPS
104 Modern Concept Science and Technology Book 5 IV. Aves The class Aves consists of birds which have strong wings for flight. Body of aves is divided into beak, head, neck, trunk and tail. They have hollow bones which makes them light for flying. They have light and fluffy feather to keep them warm and light. They have air sacs in their body. They breathe through lungs. They are oviparous and warm blooded animals. Some examples of aves are pigeon, hen, sparrow, ostrich, parrot, etc. Pigeon Hen Ostrich Parrot Fig: Some Aves V. Mammalia The class Mammalia includes the animals which have mammary glands in the females and give direct birth to their young ones. The body of mammals is divided into head, neck, trunk and tail. Most of the mammals live on land while a few live in water. They are warm-blooded animals and their body is covered with hairs. They have limbs for locomotion. But in the water living mammals Aves and mammals have four chambers in their heart. MEMORY TIPS i. Reptiles, Aves and Mammalia show internal fertilization. It means that fusion of sperm and ovum takes place inside the female body. ii. Mammals are viviparous. It means that they give direct birth to the young ones. iii. Bat is a flying mammal because it gives direct birth to the young ones. MEMORY TIPS
Modern Concept Science and Technology Book 5 105 the limbs are modified into paddles for swimming. Some examples of mammals are human beings, rat, cat, dog, bat, whale, dolphin, hippo, etc. Man Woman Bat Cow Whale Mouse Dog Cat Dolphin Fig: Mammals ACTIVITY 1 i. Observe in your surroundings and list any five animals of each class. ii. Write down any three features of each class. iii. Draw well-labelled diagram of each and show to your teacher. HOT SKILL HIGHER ORDER THINKING SKILL 1. Which of the following is a special character of mammals? a. Presence of hair or feathers over the body b. Warm blooded c. Presence of mammary gland in females d. Can live both on land and water Answer: Presence of mammary gland in females is a special feature of mammal.
106 Modern Concept Science and Technology Book 5 2. Define vertebrates with 2 examples. Animals that have backbone in their body are called vertebrates. Two examples are Human beings and Birds. 3. In which class of vertebrates do snake belong to? Snake belongs to class Reptilia. 4. List any two characteristic features of animals belong to class Pisces. Two characteristic features of animals of class Pisces are mentioned below. a. They have boat shaped (streamlined) body. b. They have fins for movement and gills for breathing. 5. Salamander is placed on class amphibia. Why? Salamander is placed on the class amphibia because it lives both in water and land during its life cycle. 6. Bat looks like birds but it is a mammal. Why? Bat is a mammal because it gives direct birth to the young ones. 7. List any two major differences between frog and fish Two major differences between the frog and the fish are mentioned below. Frog Fish a. It is an amphibian animal. a. It is an aquatic animal. b. It breathes through gills in younger stage and through lung in adult stage. b. It breathe through gills throughout their life. 33 STEPS STEPS EXERCISE EXERCISE STEP1 1. Tick (√) the correct statement and cross (x) the false one. a. Vertebrates have vertebral column. b. Jelly fish is an example of vertebrate. c. Sea horse belongs to the class Pisces. d. Amphibians have horny and rough skin. e. Aves show external fertilization. f. Mammals have four chambered heart.
Modern Concept Science and Technology Book 5 107 2. Fill in the blanks with appropriate words. a. The body of fish is covered with ____________________ . b. Amphibians can live both on _________and in __________ . c. Crocodile belongs to the class __________________ . d. The class _____includes the animals which have mammary glands. e. Bat and whale belong to the class _______________ . f. The animals present in the class ___________ are viviparous. 3. Match the following. a. Vertebrates have • Bat b. An example of Pisces • Toad c. An example of Mammal • Snake d. An example of Amphibia • Salmon e. An example of Reptile • Ostrich f. An example of Aves • Vertebral column 4. Choose the best answer from the given alternatives. a. The body of ……….. is covered with hairs. i. Mammals ii. Aves iii. Reptiles iv. Pisces b. Which of the following is a reptile? i. Bat ii. Whale iii. Rat iv. Crocodile c. Which of the following is a viviparous animal? i. Snake ii. Turtle iii. Lizard iv. Whale d. Which of the following is not a warm-blooded animal? i. Frog ii. Parrot iii. Rabbit iv. Monkey
108 Modern Concept Science and Technology Book 5 e. Which of the following is a cold-blooded animal? i. Lizard ii. Duck iii. Whale iv. Dolphin STEP2 5. Differentiate between: a. Invertebrates and vertebrates b. Salmon and Whale c. Lizard and Frog d. Bat and Pigeon e. Amphibia and Reptilia f. Horse and sea horse 6. Give reasons: a. Whale is a mammal. b. Reptiles are cold-blooded animals. c. Bat is a viviparous animal. d. Snake is grouped in the class reptiles. e. Frog shows external fertilization. 7. Name any one organism which shows the following features. a. It has fins and tail for locomotion. b. It has sticky and rolling tongue to catch the prey. c. It has horny scales over its body. d. It has hollow and light bones. e. It has mammary glands in its body. 8. Name the class and write down any two features of each. a. b. c.
Modern Concept Science and Technology Book 5 109 d. e. f. STEP3 9. Answer the following questions. a. Define vertebrates with any four examples. b. List any two salient features of the vertebrates? c. What are Pisces? Write down any three salient features and three examples of Pisces. d. What are amphibians? Write down any three salient features and three examples of amphibians. e. What are reptiles? Write down any three salient features and three examples of reptiles. f. What are aves? Write down any three salient features and three examples of aves. g. What are mammals? Write down any three salient features and three examples of mammals. 10. Draw the diagrams for: Fish, Frog, Lizard, Pigeon and Cow
110 Modern Concept Science and Technology Book 5 Key terms and terminologies of the unit 1. Flowering plants : Those plants which bear flowers in them are called flowering plants. 2. Non-flowering plants : Those plants which do not bear flowers in them are called non-flowering plants. 3. Root system : The part of a plant that grows below the surface of the ground is called root system. 4. Shoot system : The part of the plant which is found above the surface of the soil is called shoot system. 5. Stem : The part of a plant which grows upwards from the soil is called stem. 6. Leaves : Leaves are thin, flat and green parts of the plant. They sprout from the nodes of stem and branches. 7. Reticulate venations : When veins and veinlets of a leaf are arranged as a net like structure then it is called reticulate venations. 8. Parallel venations : When veins of a leaf are arranged parallel to each other then it is called parallel venations. 9. Flower : The reproductive, colourful and attractive part of a plant is called flower. 10. Bisexual flower : The flower which contains both male and female reproductive parts in it is called bisexual flower. 11. Unisexual flower : The flower which contains only one reproductive part (either male part or a female part) is called unisexual flower. 12. Receptacle : The end of the stalk that bears flower is called receptacle. 13. Pedicel : A thin and narrow stalk which joins the flower with the stem or branch is called pedicel. Sequence of Curriculum Issued by CDC Cotyledons, root, leaf and stem in monocotyledonous and dicotyledonous plant Parts of plants (root, leaf, stem, flower and fruit) and their functions UNIT Structure of the Flowering Plant 4.2 Estimated teaching periods Theory Practical 8 2 Nehemiah Grew was an English plant anatomist and physiologist, known as the "Father of Plant Anatomy". He was born in 1641 and died in 1712. By training he was a medical doctor and while working on animal anatomy he was interested about anatomy of plants. He has published his work on anatomy of flowers and most popularly presented Stamen with its pollen as male sex organ and pistil as female sex organ in a flower. Nehemiah Grew About the Scientist
Modern Concept Science and Technology Book 5 111 14. Calyx : The group of sepals which makes outermost whorl of the flower is called calyx. 15. Corolla : The group of petals which makes the second whorl of the flower next to the calyx is called corolla. 16. Androecium : The group of stamens which makes the third whorl of the flower is called androecium. 17. Gynoecium : The fourth and innermost whorl of the flower which contains pistil is called gynoecium. 18. Stigma : Stigma is the uppermost end of the pistil which receives pollen grains. 19. Style : A thin and cylindrical stalk that joins the ovary and the stigma is called style. 20. Ovary : The swollen part at the base of the pistil is called ovary. It contains ovules. 21. Fruit : The mature ovary which contains pericarp and seed is called fruit. 22. Pericarp : Pericarp is a layer of fruit that surrounds the seed. It includes epicarp, mesocarp and endocarp. 23. Epicarp : Epicarp is the outermost covering or skin of the fruit. 24. Mesocarp : Mesocarp is the fleshy part of the fruit. 25. Endocarp : Endocarp is the outermost thin layer of the seed below the mesocarp. 26. Seed : The developed ovule which is present inside the fruit is called seed. 27. Cotyledon : Cotyledon is the first leaf which is produced after the germination of seed. 28. Monocots : Those plants which contain only one cotyledon in their seeds are called monocotyledonous plants or monocots. 29. Dicots : Those plants which contain two cotyledons in their seeds are called dicotyledonous plants or dicots. Introduction There are different types of plants around us. For example, maize, mustard, pea, mango, rose, papaya, fern, etc. Some of these plants bear flower and others do not. Thus, those plants which bear flowers in them are called flowering plants. Some examples of the flowering plants are mustard, rose, papaya, apple, cauliflower, tomato, etc. Similarly, those plants which do not bear flowers in them are called non-flowering plants. For example, fern, horsetail, moss, lichens, etc. Lichen is a composite organism which is formed from algae and fungi. It is used to make litmus MEMORY TIPS
112 Modern Concept Science and Technology Book 5 Parts of a flowering plant Fig : Different parts of a flowering plant Root System The part of a plant that grows below the surface of the ground is called root system. Roots are normally white or brown in colour. Usually roots are of two different types. They are tap root and fibrous root. a. Tap root Tap root has main root called primary root. Primary root is thick and grows downwards in Fig: Types of roots Taproot Fibrous root
Modern Concept Science and Technology Book 5 113 the ground. Small roots called secondary roots form branches in the primary root. Further small roots called tertiary roots also form branches in the secondary roots. Tap root can grow deeper in the soil. Plants like soybean, apple, pea, lemon, mustard, etc. have tap root in them. b. Fibrous root Fibrous root does not contain main root or primary root. It contains a cluster of small and similar roots at the base of the stem. These roots spread in different directions. These roots are relatively weaker and cannot penetrate deeper into the soil. Plants like maize, rice, millet, grass and wheat have tap root system. Functions of roots i. Roots fix the plant strongly in the ground. ii. Roots absorb water and minerals from the soil. ACTIVITY 1 Compare the roots of maize or wheat plant with that of mustard or soybean or pea plant. Shoot System The part of the plant which is found above the surface of the soil is called shoot system. Different parts of a plant like stem, branches, leaves, flowers, buds, fruits make shoot system. Stem The part of a plant which grows upwards from the soil is called stem. Stem is thicker at the base and thinner as it move, towards the tip. Generally, herbs have thin, weak and Monocotyledonous plants have fibrous root system and dicotyledonous plants have tap root system. MEMORY TIPS Fig: Stem
114 Modern Concept Science and Technology Book 5 green coloured stem. Shrubs and trees usually have strong, woody and brown coloured stem having many branches. Branches bear sub-branches, leaves, flowers, buds, fruits, etc. Branches sprout from the certain point of the stem called nodes. Distance between two nodes in the stem is called internode. Functions of stem i. Stem provides support to the plant to stand erect. ii. It transports water and minerals from roots to leaves for photosynthesis. iii. Green stem prepares food for the plant. iv. Stem transports food from leaves to other parts of the plant. v. Stem bears and supports branches, leaves, flowers and fruits. Leaf Leaves are thin, flat and green parts of the plant which sprout from the nodes of stem and branches. Most of the leaves are green in colour due to presence of chlorophyll. The shapes and sizes of the leaves differ from plants to plants. A leaf mainly consists of three parts. They are leaf base, petiole and lamina. Petiole is a short narrow and thin stalk of a leaf. It joins leaf to the stem or branches. The lamina of a leaf contains tiny numerous pores called stomata. Lamina is the flat green portion of a leaf. A typical leaf has a long white to light green structure called midrib. Midrib runs from petiole to its apex. Midrib has many branches of veins and veinlets. These veins and veinlets make a net like structure in the leaf. The arrangement of veins and veinlets in a leaf of the plant is called venation. When veins and veinlets of a leaf are arranged as a net like structure then Fig : Leaf Based on the venation, leaves are divided into two types. They are reticulate venation and parallel venation. MEMORY TIPS
Modern Concept Science and Technology Book 5 115 it is called reticulate venations. Leaves of plants like pea, mango, mustard, rose, etc. have reticulate venation. Reticulate venation Parallel venation When veins of a leaf are arranged parallel to each other then it is called parallel venations. Leaves of plants like maize, paddy, wheat, grass and bamboo have parallel venation. Functions of leaves i. Green leaves prepare food for the plants. This process is called photosynthesis. ii. Stomata in a leaf take in oxygen and throw out carbon dioxide during respiration. Similarly, they take carbon dioxide in and throw out oxygen during photosynthesis. iii. Stomata of a leaf remove excess water. ACTIVITY 2 Collect one leaf of each from the plants maize, paddy, wheat, sugarcane, bamboo, grass, rose, guava, pea, gram, soybean and mustard. Compare these leaves with each other and distinguish reticulate and parallel venation. Flower The reproductive, colourful and attractive part of a plant is called flower. Flowers of different plants are different from each other. They differ with each other in their shapes and sizes. Generally, a complete flower contains four major parts. They are sepals, petals, stamens and pistil. Stamen is a male reproductive part of the flower and pistil is a female reproductive part. The flower which contains both male and female reproductive parts in it is called bisexual flower. Some examples of plants having bisexual flowers are In some plants, leaves are like a needle. For example, cactus, pinus, etc. MEMORY TIPS Monocotyledonous plants have parallel venation and dicotyledonous plants have reticulate venation. MEMORY TIPS
116 Modern Concept Science and Technology Book 5 mustard, rose, tomato, sunflower, etc. Similarly, the flower which contains only one reproductive part (either male part or a female part) is called unisexual flower. Some examples of plants having unisexual flowers are pumpkin, cucumber, etc. Fig: Different types of flowers A flower arises from the stem or branches of the plant. A thin and narrow stalk which joins the flower with the stem or branch is called pedicel. The end of the stalk that bears flower is called receptacle. A complete flower contains four major whorls. They are calyx, corolla, androecium and gynoecium. Fig : Structure of a complete flower i. Calyx The group of sepals which makes outermost whorl of the flower is called calyx. It is usually green in colour. Calyx protects the flower during the bud stage. ii. Corolla The group of petals which makes the second whorl of the flower next to the calyx is called corolla. It is usually colorful and surrounds
Modern Concept Science and Technology Book 5 117 the reproductive organs. Corolla attracts insects and animals for pollination. iii. Androecium The group of stamens which makes the third whorl of the flower is called androecium. Stamens are the male reproductive organs of the flower. Androecium is present in between corolla and gynoecium. A stamen has mainly two parts. They are anther and filament. Anther is a swollen bilobed structure of the stamen. It contains pollen grains. Filament is a thin, long and cylindrical stalk which supports anther. iv. Gynoecium The fourth and innermost whorl of the flower which contains pistil is called gynoecium. It is female reproductive part of the flower. A pistil is divided into three different parts. They are stigma, style and ovary. Stigma is the uppermost end of the pistil which receives pollen grains. A thin and cylindrical stalk that joins the ovary and the stigma is called style. The swollen part at the base of the pistil is called ovary. It contains ovules. After fertilization, ovules develop into seeds and ovary develops into fruit. ACTIVITY 3 Collect a bisexual flower and a unisexual flower from the garden. Identify the differences between them. Write down the detail description of these flowers and share the information with your friends. Fruit The mature ovary which contains seeds is called fruit. It is developed after fertilization. Generally, fruits are soft and fleshy. However, some fruits may be dry and hard. Different kinds of fruits have different shapes, sizes and tastes. Fig : Structure of a fruit
118 Modern Concept Science and Technology Book 5 A typical fruit contains two parts. They are pericarp and seed. Pericarp is a layer of fruit that surrounds the seed. It can be divided into epicarp, mesocarp and endocarp. Epicarp is the outermost covering or skin of the fruit. Mesocarp is the fleshy part and endocarp is the outermost thin layer of the seed below the mesocarp. Functions of a Fruit i. Fruit protects seeds from external factors. ii. Fruit stores food material. iii. Fruit helps in dispersal of seeds. ACTIVITY 4 Collect any four different kinds of fruits like mango, apple, papaya, guava, etc. from the garden or market. Observe these fruits and identify fruits having one seed and fruits having many seed. Seed The developed ovule which is present inside the fruit is called seed. In favourable condition, seed germinates into an embryo. Embryo is a baby plant which develops into a new plant. Different plants have different types of seeds. They differ in shapes, sizes and colours. Mango seed Apple seed Pumpkin seed Fig: Seeds Seed germinates into an embryo having one or two leaves. These leaves are called cotyledons. Thus, cotyledon is a first leaf which is produced after the germination of seed. On the basis of number of cotyledons, flowering plants are of two types. They are monocotyledonous plants or monocots and dicotyledonous plants or dicots.
Modern Concept Science and Technology Book 5 119 a. Monocotyledonous Plants Those plants which contain only one cotyledon in their seeds are called onocotyledonous plants. Some examples of monocotyledonous plants are sugarcane, onion, bamboo, paddy, wheat, millet, maize. These plants have fibrous root system. They have elongated leaves with parallel venation. In the stem of monocotyledonous plants, nodes and internodes are distinct. Sugar can Maiz Wheat Fig : Monocotyledonous plants b. Dicotyledonous Plants Those plants which contain two cotyledons in their seeds are called dicotyledonous plants. For example, mustard, pea, gram, apple, mango, orange, peach, soybean. These plants have tap root system. The leaves of these plants are short and flat with reticulate venation. In the stem of dicotyledonous plants, nodes and internodes are not distinct. Mustard plant Orange tree Mango tree Fig : Dicotyledonous plants
120 Modern Concept Science and Technology Book 5 Differences between monocotyledonous and dicotyledonous plants Monocotyledonous plants Dicotyledonous plants i. They have only one cotyledon in their seeds. ii. They have fibrous root system. iii. Leaves are elongated with parallel venation. iv. Stems have distinct nodes and inter- nodes. i. They have two cotyledons in their seeds. ii. They have tap root system. iii. Leaves are flat with reticulate venation. iv. Stems do not have distinct nodes and internodes. ACTIVITY 5 Collect the seeds of any five monocotyledonous plants and five dicotyledonous plants. Paste these seeds in your activity book. HOT SKILL HIGHER ORDER THINKING SKILL 1. Which of the following plants has tap root system? a. Mango b. Maize c. Sugarcane d. Grass Answer: Mango has tap root system. 2. What type of leaves do dicot plants have? Dicot Plants have flat leaves with reticulate venation. 3. What is the reproductive part of the plant? Name the male and female reproductive part. Flower is the reproductive part of the plant. Androecium is the male reproductive part while gynoecium is the female reproductive part. 4. Define shoot system. The part of the plant which is found above the surface of the soil is called shoot system. 5. Why is pea called a dicotyledonous plant? Pea is called a dicotyledonous plant because it has two cotyledons in its seed.
Modern Concept Science and Technology Book 5 121 6. Differentiate androecium and gynoecium. Androecium Gynoecium a. It is the male reproductive part of the plant. a. It is the female reproductive part of the plant. b. It produces pollen grains. b. It produces ovules. 7. List any four contrasting features of monocotyledonous plants Four features of monocotyledonous plants are: i. They have only one cotyledon in their seeds. ii. They have fibrous root system. iii. Leaves are elongated with parallel venation. iv. Stems have distinct nodes and inter- nodes. 33 STEPS STEPS EXERCISE EXERCISE STEP1 1. Tick (√) the correct statements and cross (x) the false ones. a. The plants which bear flowers are called flowering plants. b. Shoot is the underground part of a plant. c. Apple and mango have tap root system. d. Nodes and internodes are distinct in sugarcane. e. Branches sprout from the antinodes. f. Anther contains pollen grains in its sac. g. After fertilization ovule develops into fruit. h. Seed germinates into new plant. 2. Fill in the blanks with appropriate words. a. The secondary roots develop from __________________ roots. b. ______________ root system contains the cluster roots at the base of the stem. c. _________________ is a short narrow and thin stalk of a leaf. d. Stomata of a leaf remove excess ______________ from the plant.
122 Modern Concept Science and Technology Book 5 e. The end of the stalk that bears flower is called _____________ . f. _______________ attracts insects and animals for pollination. g. The outermost skin of the fruit is called _____________ . 3. Match the following. a. Roots • Prepare food for the plant b. Leaves • Absorb water and minerals c. Stem • It is a developed ovary d. Flower • The baby plant e. Fruit • Reproductive part of the plant f. Embryo • Conduct food and water 4. Tick (√. the best answer from the given alternatives. a. Which one of the following has tap root system? i. Maize ii. Barley iii. Mango iv. Wheat b. Which of the following is a female reproductive part of a flower? i. Calyx ii. Corolla iii. Androecium iv. Gynoecium c. Which of the following is a male reproductive part of a flower? i. Calyx ii. Corolla iii. Androecium iv. Gynoecium d. Which is kitchen of the plant? i. Leaf ii. Stem iii. Root iv. Flower e. Which protects the flower during bud stage? i. Calyx ii. Corolla iii. Androecia iv. Gynoecia f. Which is a feature of monocotyledonous plants? i. Tap root ii. Long leaf iii. Fibrous root iv. Two seed leaf g. Which is obtained after fertilization? i. Ovary ii. Stamen iii. Fruit iv. Corolla
Modern Concept Science and Technology Book 5 123 STEP2 5. Differentiate between: a. Tap root system and fibrous root system b. Reticulate venation and parallel venation c. Petal and sepal d. Pistil and stamen e. Monocotyledonous and dicotyledonous plants 6. Give reasons. a. Leaf is the kitchen of the plant. b. Flower is called the reproductive part of the plant c. Petals help in pollination. d. Apple is a dicotyledonous plant. e. Rose is a bisexual flower. 7. Answer in one word. a. What is the name of the underground part of the plant? b. Which is kitchen of the plant? c. The flower which has calyx, corolla, androecium and gynoecium is called? d. What type of roots does sugarcane have? e. Which part of the flower gives fruit after fertilization? f. What is the seed leaf called? 8. Label the parts of the given figures.
124 Modern Concept Science and Technology Book 5 STEP3 9. Answer the following questions. a. Define flowering and non-flowering plants. b. What are root system and shoot systems? c. List any two major functions of roots. d. Name two types of root systems with an example of each. e. Define nodes and internodes. f. Write any two important functions of stem? g. What is meant by venation in leaves? h. Write two important functions of leaves. i. Mention the different whorls of the flower with one important function of each. j. What is fruit? How does it form? k. What is seed? How does it form? l. What is a cotyledon? m. Define monocotyledonous plants with any four examples. n. What are dicotyledonous plants? Write any four examples. 10. Draw a well labelled diagram for each of the following. a. A complete mustard plant showing root system and shoot system. b. A complete flower showing calyx, corolla, androecium and gynoecium. c. Internal structure of a fruit.
Modern Concept Science and Technology Book 5 125 Life Process
126 Modern Concept Science and Technology Book 5 Sequence of Curriculum Issued by CDC Life processes (nutrition, respiration, excretion, transport and reproduction) in plants and animals Differences of plants and animals based on their life processes UNIT Life Process 5 Estimated teaching periods Theory Practical 11 4 Jan Ingenhousz was a Dutch born British physician and scientist. He was born in 1730 in Netherlands and died in 1799 in England. He was best known for his discovery of the process of photosynthesis in plants. He discovered that green plants in sunlight absorb carbon dioxide and release oxygen. This was a great milestone in understanding life process in plant. Jan Ingenhousz About the Scientist Key terms and terminologies of the unit 1. Life processes : Those activities which are performed by living organisms for their survival are called life processes. 2. Nutrients : Nutrients are those substances which are required by the body of living organisms for their proper growth and development. 3. Nutrition : The process by which living beings obtain food and utilize the nutrients present in it is called nutrition. 4. Photosynthesis : Photosynthesis is a process of manufacturing food by the green plants using carbon dioxide and water in the presence of sunlight. 5. Autotrophs : Autotrophs are those green plants which manufacture their own food by using carbon dioxide and water in the presence of sunlight. 6. Autotrophic nutrition : The mode of nutrition which is shown by autotrophs or producers is called autotrophic nutrition. 7. Heterotrophs : Those living organisms which depend upon others for their food are called heterotrophs or consumers. 8. Heterotrophic nutrition: The mode of nutrition which is shown by heterotrophs is called heterotrophic nutrition. 9. Herbivores : Those animals which feed only on plants or parts of plant are called herbivores. They are also called primary consumers. 10. Carnivores : Those animals which feed on flesh of other animals are called carnivores. They are also called secondary consumers. 11. Top consumers : Animals which feed on secondary consumers are called tertiary consumers or top consumers. 12. Omnivores : Those animals which feed on both animals and plants are called omnivores.
Modern Concept Science and Technology Book 5 127 13. Saprophytes : Those organisms which depend upon dead and decaying organic matter for their food are called saprophytes. 14. Parasites : Those animals which depend on host for their food are called parasites. 15. Respiration : The process by which energy is released by the oxidation of digested food material is called respiration. 16. Breathing : Inhaling oxygen and exhaling carbon dioxide through breathing organs of the body is called external respiration or breathing. 17. Internal transport : The process of carrying different substances from one place to another place within the body of an animal or a plant is called internal transport. 18. Xylem : Xylem transports water and minerals from roots to leaves. 19. Phloem : Phloem transports prepared food from leaves to different parts of the plant. 20. Excretion : The process of removing harmful substances from the body of living organisms is called excretion. 21. Nephridia : Nephridia are the excretory organs of the earthworms. 22. Malphigian tubules: Malphigian tubules are the excretory organs of many insects. 23. Stomata : Stomata are the small pores present in the leaves of the plants. Plants remove unnecessary carbon dioxide, excess water, oxygen, etc. through these stomata. 24. Reproduction : Reproduction is a biological process in which living beings produce their own kind. 25. Food chain : The process of transferring food energy by eating and being eaten in called food chain. 26. Ecosystem : The self-sustaining unit of biosphere which contains living organisms interacting with each other and with the environment is called ecosystem. Introduction All living organisms perform various activities which make them living. Some of these activities are digestion, growth, circulation, respiration, excretion, reproduction, sensitivity, etc. These activities are essential for the survival of life. These activities are called life processes. Thus, those activities which are performed by living organisms for their survival are called life processes. In this unit we will discuss some major life processes which are performed by animals and plants. Nutrition Both plants and animal need food to survive. Food contains necessary nutrients which are required by the living beings. These nutrients provide energy for their growth and to perform various activities. Thus, nutrients are those substances that are required by the body of living organisms for their proper growth and development. Broadly, nutrients are divided into carbohydrates, proteins, fats, vitamins and minerals. The process by which living beings obtain food and utilize the nutrients present in it is called nutrition.
128 Modern Concept Science and Technology Book 5 Modes of Nutrition Plants and animals have different modes of nutrition. They are: i. Autotrophic nutrition and ii. Heterotrophic nutrition Autotrophic Nutrition Green plants can prepare their own food them-selves. This process is called photosynthesis. Thus, photosynthesis is a process of manufacturing food by the green plants using carbon dioxide and water in the presence of sunlight. This is a reason why green plants are known as autotrophs or producers. The mode of nutrition which is shown by autotrophs or producers is called autotrophic nutrition. Heterotrophic Nutrition Animals and non-green plants do not have chlorophyll. They cannot prepare their own food themselves. They depend directly or indirectly on plants for their food. They are called heterotrophs or consumers. Thus, those living organisms which depend upon others for their food are called heterotrophs or consumers. Similarly, the mode of nutrition which is shown by heterotrophs is called heterotrophic nutrition. Some animals like cow, goat, buffalo, deer, monkey and pigeon feed only on plants or parts of plant. So, they are called herbivores. Animals like lion, tiger, leopard, snake and vulture feed on flesh of other animals. So, they are called carnivores. Similarly, human, bear, fox, dog, cat, etc. feed on both animals and plants. So, they are called omnivores. Living organisms which prepare their own food by using inorganic substances are called autotrophs or producers. MEMORY TIPS Fig: Photosynthesis in green plants Animals which depend upon dead and decaying organic matter for their food are called saprotrophs. For example vulture. MEMORY TIPS
Modern Concept Science and Technology Book 5 129 Those organisms which depend upon dead and decaying organic matter for their food are called saprophytes. For example, non-green plants like mushroom, mucor, yeast, etc. Some animals like mosquito, round worm, tapeworm, leech, bed bug, etc. depend on host for their food. They are called parasites. Omnivorous (a) (a) (a) (b) (b) (b) (a) (b) Herbivorous Parasites Saprophytes Carnivorous Fig: Heterotrophs All organisms like herbivores, carnivores, omnivores, saprophytes and parasites are called heterotrophs. They directly or indirectly depend upon plants for their food. Respiration To perform various activities living beings need energy. This energy is obtained when the digested food gets oxidized inside the body. To oxidize food material oxygen gas is required. Thus, the process by which energy is released by the oxidation of digested food material with the help of oxygen is called respiration. After an animal takes food, digestion process starts inside the body. Nutrients are absorbed and transported to each and every part of the body. Internal transport system of the animal body finally carries nutrients to each and every cell of the body. Oxidation of the absorbed food materials inside the mitochondria of a cell is called internal respiration or cellular respiration. In this process energy is released. MEMORY TIPS
130 Modern Concept Science and Technology Book 5 Similarly, internal transport system of the plant also carries nutrients from leaves to different parts of the plant. When living beings breathe in oxygen, the oxygen gas reaches each and every cell of the body. The oxygen gas reacts with the food materials in the mitochondria. As a result of this energy is released along with water and carbon dioxide. The byproduct carbon dioxide is exhaled from the body. Inhaling oxygen and exhaling carbon dioxide through breathing organs of the body is called external respiration or breathing. Protozoa breathe through general body surface, insects breathe through spiracles, fish breathe through gills, etc. Similarly, other vertebrates like amphibians, reptiles, birds and mammals breathe through lungs and plants breathe through the stomata. Gills of fish Spiracle of Insects Lungs Stomata Fig: Respiratory organs Internal Transport The process of carrying different substances from one place to another place within the body of an animal or a plant is called internal transport. This process carries food, water, minerals, oxygen, carbon dioxide, waste products, etc. from one part to the respective parts. In unicellular organisms, internal transport occurs through cytoplasm. Circulatory system and lymphatic system are the major transport systems in human body and the developed vertebrates. Circulatory system circulates blood throughout the body. Blood carries digested food, water, oxygen, carbon dioxide and other substances. Lymphatic Fig : Internal transport in animals
Modern Concept Science and Technology Book 5 131 system transports white blood cells, bacteria, viruses, etc. Xylem and phloem are the vascular tissues found in plants. They transport water, minerals and food. Xylem transports water and minerals from roots to leaves. Similarly, phloem transports prepared food from leaves to different parts of the plant. Excretion Living organisms perform various life processes in their body. During these processes, they release different kinds of substances. Some of these substances may be harmful or toxic. The body of living organisms has a mechanism to eliminate such harmful substances. This is called excretion. Thus, the process of removal of harmful substances from the body of living organisms is called excretion. Various excretory organs are responsible to remove waste materials from the body. In unicellular organisms, excretion takes place through general body surface. Nephridia are the excretory organs of the earthworms. Many insects excrete through malphigian tubules. Gills in fish and lungs in other vertebrates remove carbon dioxide from the body. Carbon dioxide, urea, excess water, mineral salts, undigested food, etc. are some waste materials which are produced in the developed vertebrates and human body. These different substances are removed from the body by different excretory organs like lungs, kidneys, nose, skin, intestine, liver, etc. Plants also remove unnecessary carbon dioxide, excess water, oxygen, etc. through stomata. Lungs Stomata Skin Kidney Fig: Excretory organs Fig : Internal transport in plants Resin, latex, gum, etc. are some excrete substances of the plants. They are useful to us. MEMORY TIPS
132 Modern Concept Science and Technology Book 5 Reproduction All living organisms produce their own kind. It is called reproduction. It is an important biological process. Reproduction may occur by sexual or asexual method. Sexual reproduction requires both male and female but asexual reproduction requires only one parent. Thus, reproduction is a biological process in which living beings produce of their own kind. Insects, fish, reptiles, amphibians, birds, etc. reproduce by laying eggs. After hatching, eggs give their young ones. Mammals like cat, dog, cow, goat, rat, rabbit, humans, etc. give direct birth to young ones. Plants can reproduce by stem, leaves, buds, spores, seeds, etc. Flowering plants reproduce through seeds. In the favourable condition seeds germinate into new plants. Hen with eggs and chick Woman with baby Germinating Seeds Fig: Reproduction Interrelationship between Plants and Animals Plants are producers and they produce food. Animals are consumers and depend upon plants for their food. Consumers are divided into three levels. They are primary consumers, secondary consumers and tertiary consumers. a. Primary consumers Animals which feed on plants or parts of plants are called primary consumers. They are also called herbivores. For examples, cow, deer, mouse, grasshopper, pigeon and monkey. Reproduction is an important biological process to continue life on the earth. In absence of reproduction all living organisms will disappear from this world. MEMORY TIPS
Modern Concept Science and Technology Book 5 133 b. Secondary consumers Animals which feed on primary consumers are called secondary consumers. They are also called carnivores. For examples, frog, snake, leopard and tiger. c. Tertiary consumers Animals which feed on secondary consumers are called tertiary consumers or top consumers. For example, hawk, eagle, shark and big fish. Some consumers like humans, crow, bear, fox, etc. feed on both primary and secondary consumers. They are called omnivores. Grass (producer) Deer (primary consumer) Tiger (secondary consumer) In the grassland, deer feeds on grass and tiger feeds on deer. Similarly, grasshopper feeds on grass, frog feeds on grasshopper, snake feeds on frog and hawk feeds on snake. When top carnivores like tiger, hawk, etc. die, they are eaten by decomposers. Micro-organisms, fungi, etc. are some examples of the decomposers. Decomposers break down the dead body of plants and animals after their death. After breaking down the complex dead body, the simple substances mix into the soil. Plants absorb these substances from the soil and prepare their food. Grass (producer) Grasshopper (Primary consumer) Frog (Secondary consumer) Snake (Tertiary consumer) From the above discussion it is clear that energy transfers from producers to different levels of consumers. Thus, the process of transferring food energy by eating and being eaten is called food chain. This relation shows that plants and animals are depended upon each other for their food. Apart from food, animals are depended upon plants for their shelter. Plants Decomposers are also called the natural cleaners because they break down the dead body of the animals and plants and turn into simple substances. MEMORY TIPS
134 Modern Concept Science and Technology Book 5 are home for insects, birds and arboreal animals. Human beings also use timber to make their shelter. Plants also provide fabrics, medicines, etc. for human beings. Difference in life process in plants and animals From the above discussion, we observed that the same life processes are found in plants and animals. However, they have different parts to carry out the different life processes. Let us look at the chart below to learn the differences in life processes among plants and animals. Life Processes Plants Animals Nutrition Prepare their own food by photosynthesis Eat plants and other animals for their food Respiration Part to support respiration is stomata Organs to support respiration are gills, lungs, moist skin, spiracles etc. Internal transport Xylem and phloem are major conducting tissues for internal transport Circulatory system (heart, blood capillaries, veins etc.) and lymphatic system (lymph nodes) are internal transport system Excretion Stomata, bark etc. excrete waste out Lungs, kidneys, skin etc. excrete waste out Reproduction Through seeds, spores, buds, stem, etc. both sexually and asexually Through laying eggs and hatching babies, mainly sexual reproduction ACTIVITY 1 Make a food chain arranging producers, primary consumers, secondary consumers and tertiary consumers. One is done for you. Producer Primary Consumer Secondary Consumer Tertiary Consumer Paddy Grasshopper Frog Snake/Hawk
Modern Concept Science and Technology Book 5 135 Interrelationship between living beings and environment Living beings live in those places which support them. They need air, water, food, shelter, sunlight, etc. for their survival. These things can only be obtain from the environment. A green plant needs minerals, water, carbon dioxide and sunlight to prepare its own food. Plants get all these things from the environment where they grow. If plants do not get sunlight, carbon dioxide, minerals or water, they cannot prepare their food. If plants do not prepare food, animals will die and no any living things can survive. Similarly, environment also depends on living beings. Plants take in water and carbon dioxide from the environment and produce glucose and oxygen. Glucose provides energy to the plants and other living organisms. Living beings take in oxygen and give out carbon dioxide in the environment. Plants also transpire excess water to the environment through stomata. Decomposers depend upon dead animals and plants for their food. They break down dead body of animals and plants into simpler substances and release minerals into the soil. In this way, the living organisms and environment interact with each other. These interactions balance the ecosystem. Thus, the self-sustaining unit of biosphere which contains living organisms interacting with each others and with the environment is called ecosystem. In this way, living beings are interrelated with their environment. ACTIVITY 2 Fill in the blanks of the table showing the interaction between plants and animals with their environment. Living Process Components of environment needed Components of environment released 1. Photosynthesis .............................. Oxygen 2. Transpiration Water .............................. 3. ............................ Oxygen Carbondioxide 4. Decomposition Complex dead bodies ..............................
136 Modern Concept Science and Technology Book 5 HOT SKILL HIGHER ORDER THINKING SKILL 1. Which of the following is heterotrophic organism? a. Algae b. Plants c. Mushroom d. All of above Answer: Mushroom is a heterotrophic organism. 2. What is the process of producing young ones similar to parents called? The process of producing young ones similar to parents is called reproduction. 3. Define respiration. The process by which energy is released by the oxidation of digested food material with the help of oxygen is called respiration. 4. Why mushroom is called a saprophytic organism? Mushroom is called a saprophytic organism because it absorbs food (nutrients) from dead and decayed organic materials. 5. Write any two differences between producers and consumers Two differences between the producers and consumers are mentioned below in the table. Producers Consumers 1. They can prepare their food by themselves. 1. They depend upon other organisms for their food. 2. Green plants are the examples of producers. 2. Animals are the examples of consumers. 6. How does energy transfer from one trophic level to other? Explain with an example. Energy transfers from one trophic level to another trophic level through food chain. Let us take an example of grassland. Grasses prepare food by themselves through photosynthesis. Deer eats the grass and the tiger eats the deer. After the death and decay of tiger, the minerals from the body of tiger leaches to the soil. Plants absorb those minerals and use it during photosynthesis.
Modern Concept Science and Technology Book 5 137 33 STEPS STEPS EXERCISE EXERCISE STEP1 1. Tick (√) the correct statements and cross (x) the false ones. a. Growth, digestion and reproduction are life processes. b. Respiration releases energy. c. Sexual reproduction needs only one parent. d. Green plants are also called producers. e. Heterotrophs are also known as consumers. f. Bear, humans, cat, dog, etc. are omnivores. g. Phloem transports water and minerals. h. Plants release oxygen in the environment as a result of photosynthesis. 2. Fill in the blanks with appropriate words. a. Living beings get ________________ from the food. b. The mode of nutrition in green plants is called _______________ nutrition. c. Animals which depend upon dead and decayed organic matter for their food are called ______________________ . d. The reaction of digested food with oxygen is called __________ . e. ______________________ transports food from leaves to different parts of a plant. f. Herbivores feed on ____________________ . g. _________________ break down dead animals and plants into simpler substances.
138 Modern Concept Science and Technology Book 5 3. Match the following: a. Digested food contains • Fungi, bacteria, etc. b. An excretory organ • Mitochondria c. Photosynthesis needs • Nutrients d. Cellular respiration occurs • Herbivore e. Reproduction • Kidney f. Primary consumers • Carbon dioxide and water g. Decomposers • Production of their own kind 4. Tick (√. the best answer from the given alternatives. a. Which of the following is not a nutrient? i. Protein ii. Vitamin iii. Water iv. Carbohydrate b. Which conducts food in the plants? i. Xylem ii. Phloem iii. Both iv. None c. Which is an excretory organ of insects? i. Malphigian tubules ii. Spiracles iii. Lungs iv. Kidney d. Which is the top carnivore (consumer.? i. Frog ii. Snake iii. Lizard iv. Hawk e. What are bacteria? i. Producers ii. Consumers iii. Decomposers iv. None STEP2 5. Differentiate between: a. Nutrients and nutrition b. Internal respiration and external respiration c. Respiration and excretion d. Carnivores and herbivores
Modern Concept Science and Technology Book 5 139 e. Primary consumers and secondary consumers f. Producers and consumers g. Parasites and saprophytes 6. Give reasons. a. Green plants are called producers. b. Animals are called consumers. c. Cow, goat, rabbit, etc. are herbivores. d. Louse, bedbug, roundworm, etc. are parasites. e. Animals cannot survive without plants. 7. Write down answer in one word. a. The place in which internal respiration takes place is called ______ b. The mode of nutrition in animals is called ________________ . c. Breathing organ of insects is called _____________________ . d. Carnivores feed on _________________ . e. The pores of leaves which help in respiration in plants are called ___________________ . f. The resin and latex in plants are called ___________________. 8. Look at the following figures and write down their names. a. b. a. b.
140 Modern Concept Science and Technology Book 5 STEP3 9. Answer the following questions. a. Define life process with any three examples. b. What is nutrition? Write down any three examples of nutrients. c. What are autotrophs and heterotrophs? Write any two examples of each. d. What is meant by respiration? Where does cellular respiration occur? e. What is internal transport? f. Write down the function of xylem and phloem in plants. g. What is excretion? Write down three excretory organs of the human body. h. What is reproduction? What happens when there does not occur reproduction in living beings. i. Write down the main function of decomposers. j. What is food chain? Write down with an example. k. Explain how living beings are interrelated with their environment? 10. Draw a well labeled diagram for the following. a. Lungs b. Stomata c. Kidneys
Modern Concept Science and Technology Book 5 141 Unit 6 Matter Stone Brick Bag Table Air filled balloon Smoke and gases from chimney Smoke and gases from car Pencil
142 Modern Concept Science and Technology Book 5 Key terms and terminologies of the unit 1. Matter : Anything that has weight and occupies space is called matter. 2. Mass : The amount of matter contained in a body is called mass. 3. Molecules : Each and every matter is made up of small tiny particles called molecules. 4. Volume : The total space occupied by a substance is called volume. 5. Solids : Substances which have definite shape, size and volume are called solids. 6. Liquids : Substances which do not have definite shape and size but have definite volume are called liquids. 7. Gas : A substance which does not have definite shape, size and volume is called gas. Introduction We see different things around us. They may be useful or useless to us. They have different shapes, sizes and color. For example, a book, pen, pencil, chair, box, lamp, shoes, bags, clothes, air, water, water vapor, etc. These things have weight and occupy space. Anything that has weight and occupies space is called matter. For example, a brick, rock, table, chair, bag, television. Air is also matter because it has weight and occupies space. Things like light, sound, etc. do not have mass and also do not occupy space. So they are not called matter. Chair Table Car Computer Stone Sequence of Curriculum Issued by CDC Introduction to matter Physical properties of matter Comparison of physical properties of solids, liquids and gases UNIT State of Matter 6.1 Estimated teaching periods Theory Practical 8 2 Carl von Linde was a German engineer. He was born in 1842 and died in 1934 in Germany. He was the inventor of conversion of gases into liquids in large quantities more precisely and effectively than other technologies of his time. Based on his innovation, we are operating modern technology refrigeration system. Carl von Linde About the Scientist
Modern Concept Science and Technology Book 5 143 Almost all matter differ from one another in their shape, size, color, odor, weight, volume, etc. For example, a chair differs from a table, a television set differs from a radio and water differs from ice. All matter are made up of tiny particles called molecules. We cannot see molecules with our naked eyes. To be matter, the substance must have two common properties. They are: i. The substance must have weight. ii. The substance must occupy space. i. The substance must have weight The amount of matter contained in a body is called mass. Each and every matter is made up of small particles called molecules. Matters have mass due to these molecules. A matter which has more number of molecules has more weight. Similarly, a matter which has less number of molecules has less weight. Molecules of different matter differ from each other. For example, the molecules of a brick differ from the molecules of a stone. Similarly, the molecules of plastic differ from the molecules of water. ii. The substance must occupy space The total space occupied by a substance is called volume. All matters have their own volume. Some matters occupy more space and have more volume. Similarly, matters which occupy less space have less volume. For example, a table occupies more space than a brick. In the same way, a brick occupies more space than a pen. ACTIVITY 1 To show matter has weight Take a pan balance and two balloons of equal size. Fill a balloon with air and tighten its mouth. Keep one balloon in one pan and another in another pan. What do you observe? You see that the pan with the air-filled balloon remains downward. Similarly, the pan with the unblown balloon remains upward. It mean the air-filled balloon is heavier than the empty balloon. This shows that air is matter, which has weight.
144 Modern Concept Science and Technology Book 5 ACTIVITY 2 To show matter occupies space Take a glass and keep it on a plate. Fill the glass completely with water. Take a small piece of stone. Insert the stone into the glass. When you dip the stone, water overflows from the glass and gets collected on the plate. It shows that, a piece of stone occupies space as it has volume. Again fill the glass jar with water and dip a bigger piece of stone in it. It covers more space. So, it displaces more water from the glass. In this way, we can show that matter occupies space. States of matter Generally, matter exists in three different forms. These three different forms are called the states of matter. They are: a) Solid, b) Liquid and c) Gas. a. Solids Substances which have definite shape, size and volume are called solids. Solids are hard because their molecules are closely packed. A stone, brick, paper, wood, glass, pen, pencil are some examples of solids. Properties of solids i. Solids have definite shape and size. ii. They have a fixed volume. iii. They cannot be compressed further. iiv. They have a strong force of attraction between their molecules. Stone Brick Table Bag Pencil Fig: Examples of solids
Modern Concept Science and Technology Book 5 145 b. Liquids Substances which do not have definite shape and size but have definite volume are called liquids. They flow from a higher level to a lower level. Liquids flow because the molecules of liquids are far apart from each other with less force of attraction. For example, milk, water, honey, petrol, diesel, kerosene, melted ghee, alcohol. Properties of liquids i. Liquids do not have definite shape and size. Their shape and size depend upon the vessel in which they are kept. ii. Liquids have fixed volume. Liquids cannot be compressed. iii. Liquids have a weak force of attraction between their molecules. So, they flow from a higher level to a lower level. ACTIVITY 3 To show liquids do not have fixed shape but have fixed volume Take a glass of water. Observe the shape of water in the glass. Obviously, water takes the shape of the glass. Pour water on a flat plate. Now, water takes the shape of the plate. Again, put the water in a measuring cylinder. The water takes the shape of the measuring cylinder. Has the volume of water changed? You can see that the volume of water remains the same in all cases, but the shape of water is different in different containers. Water in glass Water in measuring cylinder Water in plate Milk Water Honey Petrol Fig : Examples of luquids
146 Modern Concept Science and Technology Book 5 c. Gas A substance which does not have definite shape, size and volume is called gas. Gas spreads here and there because the molecules of gas are very far from each other. Oxygen, carbon dioxide, bad smell, smoke, air are examples of gases. We cannot see gas with our naked eyes but we can feel their effects. Properties of gases i. Gases do not have definite shape, size and volume. ii. They are highly compressible. They can be compressed into a very small container. iii. They have a very weak force of attraction between their molecules. Therefore, they spread far away from each other. ACTIVITY 4 To show that gas does not have definite shape and volume Take a bottle of perfume or body spray. Where do you think the gas is? The gas is inside the bottle of the perfume. Go to a corner of the room and ask your friends to stand in another corner. The gas spreads out in the room. Do your friends smell it? Yes, they smell the perfume. It means that the gas in a small bottle spreads all over the room. This shows that the gas does not have a fixed shape and a fixed volume. Comparison between solid, liquid and gases We are now aware of different properties of different matters. Now, let us summarize them by comparing their features. Air-filled balloon Smoke from chimney Smoke from vehicle Fig: Examples of gas Among 3 states of matters, only solids have fixed shape while solids and liquids only have fixed volume. MEMORY TIPS
Modern Concept Science and Technology Book 5 147 Properties Solids Liquids Gases Shape Fixed Takes the shape of container up to its level Takes the shape of container Volume Fixed Fixed Not fixed Space between molecules Less space, most closely packed More space, less loosely packed Large space, very loosely packed Force between molecules Very high Less high than solids Negligible Flowing ability Does not flow Flow from higher level to lower level Flows in any direction depended upon the pressure Rigidness Very rigid Less rigid Not rigid Compressing ability Cannot be compressed Cannot be compressed Highly compressed HOT SKILL HIGHER ORDER THINKING SKILL 1. What are the important requirements of matters? a. Cover space b. have mass c. None of above d. Both of above Matter have mass and covers space. 2. Which form of matter expanse more than other forms of matter? Gas expands more than other form of matter. 3. Define liquids and give three examples of it. Substances which do not have definite shape and size but have definite volume are called liquids. Three examples of liquid are milk, water and alcohol. 4. Why are solids hard in nature? Solids are hard in nature because the molecules in the solid are closely packed. 5. Differentiate between liquid and gases? Major differences between liqids and gases are mentioned in the table below. Liquids Gases i. They have fixed volume. i. Their volume changes.
148 Modern Concept Science and Technology Book 5 Liquids Gases ii. They flow from higher level to lower level. ii. They spread from high pressure to low pressure area. iii. Their molecules are far apart and have weak force of attraction. iii. Their molecules are very far apart and have very weak force of attraction iv. Examples are water, alcohol, milk etc. iv. Examples are smoke, oxygen, hydrogen etc. 6. Explain an activity to show that air has mass. We need a physical balance and 2 balloons of equal size. One balloon should be inflated and other should be left as it is. Then we need to keep each balloon in each of the pan of the physical balance. The balloon filled with the air is observed to be heavier than the empty balloon. It shows that the air has mass. 33 STEPS STEPS EXERCISE EXERCISE STEP1 1. Tick (√) the correct statements and cross (x) the false ones. a. Air does not have weight. So, it is not considered as matter. b. Matters have weight and cover some space. c. Oil does not have a fixed volume. d. Gas molecules have very strong intermolecular force of attraction. e. Solids and liquids are generally non-compressible. f. All substances are made up of tiny particles called molecules. 2. Fill in the blanks with appropriate words: a. There are ________________ states of matter. b. Matter has ______________ and occupies ______________ . c. Matter is made up of tiny particles called ______________ .
Modern Concept Science and Technology Book 5 149 d. ______________ molecules have least intermolecular force of attraction. e. Smoke is an example of ______________ . f. Liquids have a fixed ______________ but no fixed ____________ . g. Oxygen, nitrogen, carbon dioxide are some examples of ________. 3. Match the following words with their pairs: a. Liquids i. The total matter contained in a body b. Gases ii. The total space occupied by a substance c. Solids iii. Has weight and occupy space d. Matter iv. No definite shape, size and volume e. Volume v. Definite shape, size and volume f. Mass vi. Definite volume but no definite shape and size 4. Select the correct alternatives. a. Matters have : i. Only volume ii. Only weight iii. Both volume and weight iv. None b. Which is an example of solid? i. Petrol ii. Diesel iii. Kerosene iv. Cotton c. Which is an example of liquid? i. Desk ii. Chair iii. Kerosene iv. Clothes d. Which is an example of gas? i. Kerosene ii. Milk iii. Perfume iv. Honey e. Which has the largest distance in their molecules? i. Solid ii. Liquid iii. Gas iv. Plastic f. Which has the least distance in their molecules? i. Solid ii. Liquid iii. Gas iv. All g. Whose molecules are highly compressible? i. Solid ii. Liquid iii. Gas iv. All
150 Modern Concept Science and Technology Book 5 STEP2 5. Differentiate between: a. Solid and liquids b. Liquids and gases c. Brick and alcohol d. Smoke and stone 6. Give reasons: a. Wood is a solid matter. b. Liquids flow from a higher level to a lower level. c. Gases spread everywhere. d. Water is a liquid. 7. Identify the following figures and classify into solid, liquid and gas. STEP3 9. Answer the following questions. a. Define matter with any five examples. b. What are the three different states of matter? c. What are solids? Write down any three characteristics and four examples. d. Define liquids with three characteristics and four examples. e. What are gases? Write down any three characteristics and four examples. f. What are molecules? g. Define volume. 10. Explain an activity to show that air has weight. 11. Explain an activity to show that gas does not have a fixed volume.