e. Withering of leaves and buds occur due to lack of .........................
Potassium fertilizers Phosphorus fertilizers
Nitrogenous fertilizers Organic fertilizers
2. Answer the following questions.
a. What are fertilizers?
b. Name two types of fertilizers on the basis of source.
c. What are organic fertilizers?
d. How is compost manure prepared? Explain.
e. Mention any two advantages of compost manure.
f. Write down the disadvantages of organic fertilizers.
g. Define inorganic or chemical fertilizers with any three examples.
h. Write down the advantages and disadvantages of chemical fertilizers.
i. What are nitrogen fertilizers? Give any three examples.
j. What are phosphorus fertilizers? Write examples.
k. Define potassium fertilizers with any three examples.
l. Why are nitrogen, phosphorus and potassium essential for plants?
m. What symptoms are seen in plants due to lack of:
i. nitrogen
ii. phosphorus
iii. potassium
3. Write any four points that should be considered while using chemical fertilizers.
4. Write any two differences between organic and inorganic fertilizers.
5. Describe in brief the effects of overuse of inorganic fertilizers in the environment.
Grid-based Exercise 2
Group ‘A’ (Knowledge Type Questions) (1 Mark Each)
1. What is fertilizer ?
2. What are two types of fertilizers? Write.
3. Give any two examples of nitrogenous fertilizers.
4. What is organic fertilizer ?
5. What is green organic fertilizer ?
6. What is inorganic fertilizer ?
7. What are nitrogenous fertilizers ?
8. Write any two disadvantages of chemical fertilizers.
GREEN Science (Chemistry) Book-9 251
9. What is meant by NPK fertilizers ?
10. List the effects seen in plants due to lack of phosphorus.
11. Write any two disadvantages of inorganic fertilizers.
12. List any two effects seen in plants due to lack of nitrogen.
13. What is animal organic fertilizer?
For Group ’B’ (Understanding Type Questions) (2 Marks Each)
14. Write any two differences between organic fertilizers and chemical fertilizers.
15. Why is NPK fertilizer called complete fertilizer ? Give reason.
16. The use of organic fertilizers is considered better than the use of inorganic fertilizers,
why ?
17. We should add fertilizers to the soil time to time. Give reason.
18. Potassium chloride is called inorganic fertilizer ?
19. Differentiate between nitrogenous fertilizers and organic fertilizers.
20. Organic fertilizer is not called complete fertilizer. Give reason.
For Group ‘C’ (Application Type Questions) (3 Marks Each)
21. Write any three advantages of organic fertilizers.
22. Write any three advantages of inorganic fertilizers.
23. What effects in plants can be seen due to lack of potassium ? Write. Write down the
importance of nitrogen for plants.
24. How many types of organic fertilizers are there ? What are they ? Write any two
disadvantages of chemical fertilizers.
For Group ‘D’ (Higher Abilities Type Questions) (4 Marks Each)
25. Write down the precautions while using chemical fertilizers. Differentiate between
potassium fertilizer and phosphorus fertilizer in two points.
26. Write a short note on 'Use of chemical fertilizers and its impact on environment."
27. Write down the importance of nitrogen for plants. Differentiate between green organic
fertilizer and chemical fertilizer in two points.
28. Describe in brief the importance of phosphorus for plants. Differentiate between
green organic fertilizer and animal organic fertilizer in two points.
29. Describe in brief the importance of potassium for plants. Differentiate between
nitrogenous fertilizer and phosphorus fertilizer in two points.
252 GREEN Science (Chemistry) Book-9
Biology
UNIT Classification of Plants
16 and Animals
Weighting Distribution Theory : 8 Practical: 3
Before You Begin
We see a large number of living beings in our surroundings. Among
them, some are plants. Plants may be unicellular or multicellular and
flowering or non-flowering. Similarly, animals may be unicellular
or multicellular and invertebrates or vertebrates. The living beings
differ in shape, size, structure, colour, etc. They also differ in their
habitat, feeding habit, method of reproduction, evolution, etc. It is
almost impossible to study all the living beings. So, they are grouped
into various categories to make their study easier and faster. This
process is called classification. In this unit, we will study classification
of plants and animals and life cycle of mosquito in brief.
Learning Objectives Syllabus
After completing the study of this unit, students will be able to: • Non-flowering and flowering
i. classify plants upto class, invertebrates upto phylum plants
and vertebrates upto class. • Classification of plants upto
sub-division and class
ii. explain the characteristics of plants and animals with
examples. • Classification of invertebrates
and vertebrates upto class
iii. describe the life cycle of mosquito with labelled
figures. • Life cycle of mosquito
iv. list the adverse effects of mosquito bite on human • Adverse effects of mosquito
beings.
• Mosquito control
Glossary: A dictionary of scientific/technical terms
classification : the grouping of living beings on the basis of similarities and differences
taxonomy : the biological science of classification
monocot : the flowering plants having only one cotyledon in their seed
dicot : the flowering plants having two cotyledons in their seed
bisexual : the organism having both male and female sex organs
unisexual : the organism having either male or female sex organs
GREEN Science (Biology) Book-9 253
Classification of Plants and Animals
Different types of plants and animals live on the earth. They differ in shape, size,
structure, appearance, etc. Living beings are grouped on the basis of their characteristics,
morphology (structure), feeding habit, method of reproduction and so on. The grouping
of living organisms on the basis of similarities and differences is called classification. It
makes the study of living organisms easy and systematic. Classification of plants and
animals helps us understand the relation among various groups organisms.
We have studied two kingdom system of classification in class 7. They are (i) Plant
kingdom and (ii) Animal kingdom.
In 1969 AD, an American Taxonomist Robert H. Whittaker introduced five kingdom
system of classification as follows:
1. Kingdom Monera
2. Kingdom Protista
3. Kingdom Fungi
4. Kingdom Plantae
5. Kingdom Animalia
A brief description of each kingdom of living beings is given below:
1. Kingdom Monera
Microscopic organisms having prokaryotic cell are kept in Kingdom Monera. The
organisms of this kingdom are unicellular having DNA (deoxyribonucleic acid) as
a nucleus. Their mode of nutrition may be autotrophic or parasitic. Living beings like
bacteria, blue-green algae, azotobacter are kept in Kingdom Monera.
Fig.
16.1 Blue green algae Azotobacter
Bacteria
2. Kingdom Protista
Unicellular organisms having eukaryotic cells are kept in Kingdom Protista. They have a
well developed nucleus, i.e. nucleus having chromosomes, nucleolus, nuclear membrane
and nucleoplasm.
Kingdom Protista includes unicellular animals like amoeba, paramecium, euglena,
trypanosoma, trichomonas, plasmodium, etc.
254 GREEN Science (Biology) Book-9
Fig. Fig.16.2 Paramecium Euglena Trypanosoma
Amoeba
3. Kingdom Fungi
Unicellular and multicellular organisms without chlorophyll are kept in Kingdom Fungi.
Fungi have thalloid body. They do not have chlorophyll. So they cannot prepare their
own food by photosynthesis. They depend on dead and decaying organic matter to get
their food. Their reserved is glycogen. Their cell wall is made of the mixture of chitin
and cellulose. Non-green plants like mushroom, yeast, mucor, Penicillim, etc. belong to
Kingdom Fungi.
16.3 Yeast Mucor Pencicillium
Mushroom
4. Kingdom Plantae
Different types of non-flowering plants and flowering plants are kept in Kingdom Plantae.
They have chlorophyll. They may be unicellular or multicellular. They may or may not
contain root, stem and leaves.
5. Kingdom Animalia
Different types of multicellular invertebrates and vertebrates are kept in Kingdom Animalia.
Five kingdom system of classification is more appropriate and scientific than two kingdom
system of classification because of the following reasons.
i. Living beings have been classified into prokaryotes and eukaryotes on the basis of the
type of cell.
ii. Unicellular organisms are kept separately into Kingdom Monera and Kingdom
Protista.
iii. Plants with chlorophyll or without chlorophyll are kept in separate kingdoms.
Non-flowering plants (Cryptogams) and flowering plants (Phanerogams)
The plants which do not bear flowers are called non-flowering plants. They are also called
cryptogams. Spirogyra, chlamydomonas, moss, riccia, fern, etc. are non-flowering plants.
GREEN Science (Biology) Book-9 255
The plants which bear flowers and seeds are called flowering plants. They are more
developed than non-flowering plants. They have well developed root, stem and leaves.
Sunflower, mango, rose, sugrcane, pine, cycas, etc. are some examples of flowering plants.
Kingdom Plantae
Division
Algae Bryophyta Tracheophyta
e.g. Spirogyra, e.g. Moss, Liverworts, e.g. Fern, Cycas,
Chlamydomonas, etc. etc. Sugarcane, Apple, etc.
Sub-division
Pteridophyta Gymnosperms Angiosperms
e.g. Fern, Horsetail, etc. e.g. Cycas, Pinus, etc. e.g. Bamboo, Pea, etc.
Class
Monocotyledon Dicotyledon
e.g. Wheat, Maize, etc. e.g. Pea, Bean, etc.
On the basis of structure and development, Kingdom Plantae is divided into three
divisions. They are as follows:
1. Division Algae
2. Division Bryophyta
3. Division Tracheophyta
A brief description of each division of Kingdome Plantae is given below:
1. Division Algae
This sub-division consists of green thallophytes. They are found in water and moist places.
Fig.
16.4 Chlamydomonas Volvox
Spirogyra
Characteristics
1. The plant body is a green thallus.
2. Chlorophyll is present. So they can prepare their own food by photosynthesis.
3. The cell wall is made of cellulose.
256 GREEN Science (Biology) Book-9
4. They may be unicellular (Chlamydomonas) or multicellular (Spirogyra)
5. The mode of nutrition is autotrophic.
6. They store food in the form of starch.
7. They reproduce asexually or sexually.
Examples: Chlamydomonas, spirogyra, volvox, etc.
Activity 1
Observe different types of algae and fungi in your locality. Collect them and study
their characteristics one by one.
Draw a neat and labelled figure of each.
2. Division Bryophyta Do You Know
This division includes multicellular non- Bryophytes grow on moist and they need
flowering plants that grow on moist land water to reproduce. Therefore, bryophytes
and need water to reproduce. are also called amphibian plants.
Fig.
16.5 Riccia Moss
Marchantia
Characteristics
1. The plant body is multicellular which may be thalloid (e.g. liverworts) or leafy (moss).
2. Chlorophyll is present.
3. True root, stem and leaves are absent.
4. They are attached to the soil with the help of rhizoids.
5. Vascular tissues (xylem and phloem) are absent.
6. Their mode of nutrition is autotrophic.
7. They need water for reproduction.
8. They show alternation of generations in their life cycle.
Examples: Marchantia (liverworts), Riccia, Moss, etc.
3. Division Tracheophyta
Well developed plants having vascular tissues are kept in division Tracheophyta. These
plants may be non-flowering or flowering. They have well developed root, stem and
leaves. They have well developed xylem and phloem tissues.
GREEN Science (Biology) Book-9 257
Fig. Fig.16.6
Fern Cycas Pea plants Maize plants
Division Tracheophyta is further divided into three sub-divisions. They are as follows:
1. Sub-division Pteridophyta
2. Sub-division Gymnosperms
3. Sub-division Angiosperms
1. Sub-division Pteridophyta
This division consists of well developed cryptogams having feather-shaped leaves.
Pteridophytes are commonly found in moist, shady and cool places.
16.7 Lycopodium Horsetail
Fern
Characteristics
1. The plant body can be divided into rhizoids (root), rhizome (stem) and leaves.
2. Feather-shaped leaves are present.
3. Vascular tissues (xylem and phloem) are present.
4. The mode of nutrition is autotrophic.
5. Flowers and seeds are absent.
6. They show alternation of generations in their life cycle.
Examples: Fern, Lycopodium, Horsetail (Equisetum), etc.
2. Sub-division Gymnosperms
This division consists of cone bearing plants having naked seeds. They are commonly
found in cold and dry places.
258 GREEN Science (Biology) Book-9
Fig. Fig.16.8 Pine Pine cone
Cycas
Characteristics
1. Seeds are naked.
2. Cones are present instead of true flowers.
3. Needle-shaped leaves are present.
4. They do not have fruits due to absence of ovary.
5. Male cones and female cones are separate.
Examples: Cycas, pine, cedar, juniper, etc.
3. Division Angiosperms
This division consists of the most developed flowering plants having fruits. They are
found on land and in water.
16.9 Maize Mango Rose
Pea
Characteristics
1. True flowers are present.
2. Seeds are enclosed inside the fruit.
3. They may be herbs, shrubs or trees.
4. Vascular tissues are well developed.
5. These plants may be small to very large in size.
6. Their mode of nutrition is autotrophic.
7. They bear fruits and seeds.
Examples: Maize, rose, apple, mustard, sugarcane, onion, garlic, orange, mango, sal,
sissoo, simal, etc.
GREEN Science (Biology) Book-9 259
On the basis of number of cotyledons in a seed, division Angiosperms is divided into two
classes. They are as follows:
1. Class Monocotyledons 2. Class Dicotyledons
1. Monocotyledons
This sub division includes flowering plants having only one cotyledon in their seeds.
Fig. Fig.16.10 Bamboo Sugarcane Onion
Maize
Characteristics
1. A seed contains only one cotyledon.
2. Fibrous root system is present.
3. Leaves are elongated having parallel venation.
4. Nodes and internodes are distinct.
5. The plant body consists of roots, stem and leaves.
6. Flowers, fruits and seeds are present.
Examples: Maize, sugarcane, bamboo, onion, garlic, grass, paddy, wheat, barley, etc.
2. Dicotyledons
This class includes well developed flowering plants having two cotyledons in their seeds.
16.11 Sunflower Mango Apple
Beans
Characteristics
1. A seed contains two cotyledons.
2. Tap root system is present.
3. Leaves are broad having reticulate venation.
4. Nodes and internodes are not distinct.
5. Vascular tissues are well developed.
260 GREEN Science (Biology) Book-9
6. Well developed flowers are present.
Examples: Rose, mango, apple, bean, pea, mustard, orange, lotus, sunflower, etc.
Differences between Gymnosperms and Angiosperms
Gymnosperms Angiosperms
1. Cones are present. 1. Cones are absent.
2. Fruits are absent. 2. Fruits are present.
3. Seeds are naked. 3. Seeds are enclosed.
4. Leaves are pointed. 4. Leaves are flat and broad.
Differences between Monocot and Dicot
Monocot Dicot
1. A seed contains only one cotyledon. 1. A seed contains two cotyledons.
2. Fibrous root system is present. 2. Tap root system is present.
3. Leaves are elongated having parallel 3. Leaves are broad having reticulate
venation. venation.
Classification of Some Plants
a. Volvox b. Riccia : Plantae
: Bryophyta
Kingdom : Plantae Kingdom : Riccia
Division
Division : Algae Type
Type : Volvox
c. Fern d. Cycas : Plantae
Kingdom : Plantae Kingdom
Division : Tracheophyta Division : Tracheophyta
Sub-division : Pteridophyta Sub-division : Gymnosperms
Type : Fern Type : Cycas
e. Sugarcane f. Mustard : Plantae
Kingdom : Plantae Kingdom
Division : Tracheophyta Division : Tracheophyta
Sub-division : Angiosperms Sub-division : Angiosperms
Class : Monocotyledon Class : Dicotyledon
Type : Sugarcane Type : Mustard
GREEN Science (Biology) Book-9 261
Activity 3
Observe different types of flowering plants in your locality.
Study their morphology and classify them in terms of gymnosperms,
angiosperms, monocot and dicot and fill in the given table.
Flowering plants Gymnosperms Angiosperms
1. 1. 1.
2. 2. 2.
3. 3. 3.
4. 4. 4.
5. 5.
6. Monocot Dicot
7. 1. 1.
8. 2. 2.
9. 3. 3.
10. 4. 4.
5. 5.
Invertebrates
Animals like earthworm, mosquito, grasshopper, butterfly, dragonfly, honeybee,
cockroach, leech, snail, slug, etc. do not have backbone or vertebral column. These animals
are called invertebrates. They are primitive animals having less developed organs and
systems. Invertebrates are those animals which do not have backbone or vertebral column.
Examples: Amoeba, sponge, hydra, tapeworm, roundworm, earthworm, butterfly, snail,
starfish, etc.
Fig.
16.12 Butterfly Earthworm Snail
Tapeworm
Characteristics of Invertebrates
1. Invertebrates do not have backbone or vertebral column.
2. Some of them are unicellular and the rests are multicellular.
262 GREEN Science (Biology) Book-9
3. Their organs and systems are less developed.
4. Their body may have a hard protective covering.
5. They are found in water, land and air.
Classification of Invertebrates
On the basis of structure and development, invertebrates are classified into eight phyla.
They are as follows:
1. Porifera 2. Coelenterata
3. Platyhelminthes 4. Aschelminthes
5. Annelida 6. Arthropoda
7. Mollusca 8. Echinodermata
1. Phylum Porifera
Phylum Porifera consists of primitive multicellular animals having numerous pores in
their bodies. They are commonly known as sponges.
Habitat
Sponges are commonly found in water, i.e. fresh water and marine water. Their body
remains attached to the substratum with the help of basal disc.
Salient features
a. They have numerous pores on their bodies. The small pores are called ostia and large
pores are called oscula.
b. They are multicellular animals.
c. Their body remains attached to the surface of rocks, woods, etc. with the help of basal
disc.
d. They are diploblastic animals.
e. They don’t have head, eyes and legs.
f. Breathing takes place through the body surface.
Examples: Sycon, Spongilla, Euspongia, etc.
Fig.
16.13 Spongilla Euspongia
Sycon
GREEN Science (Biology) Book-9 263
2. Phylum Coelenterata
Phylum Coelenterata consists of aquatic invertebrates having hollow body cavity called
coelenteron.
Habitat
Coelenterates are found in fresh water and marine water. They live in pond, lake and sea.
Salient features
a. Coelenterates have a coelenteron, i.e. hollow body cavity.
b. Mouth is present but anus is absent.
c. Mouth remains surrounded by tentacles.
d. Breathing takes place through general body surface.
e. They reproduce by budding or regeneration.
f. They are diploblastic animals.
g. Locomotion takes place with the help of tentacles.
Examples: Hydra, Sea anemone, Coral, etc.
Fig.
16.14 Sea anemone Coral
Hydra
3. Phylum Platyhelminthes
Phylum Platyhelminthes consists of invertebrates having flat body. These animals are
commonly known as flatworms.
Habitat Do You Know
Flatworms live as parasites of animals. They
are found in the intestine or liver of cow, Parasites are organisms that take food and
buffalo, pig, human, dog, etc. shelter from their hosts, e.g. tape worm,
liver fluke, mosquito, etc.
Salient features
a. Their body is flat which may be leaf- The animals having male and female
reproductive organs in the same body
like, ribbon-like or tape-like. are called bisexual animals, e.g. tape
b. Their body may be segmented (e.g. tape worm, liver fluke, etc.
worm) or unsegmented (e.g. Liver fluke). Host is an organism which provides
c. They are bisexual animals. food and shelter to a parasite.
d. They suck blood from their hosts with
the help of suckers.
264 GREEN Science (Biology) Book-9
e. They are triploblastic animals.
f. Suckers and hooks are present.
g. They reproduce asexually or sexually.
Examples: Tapeworm, Liver fluke, Planaria, etc.
Fig. Fig.16.15 Liver fluke Planaria
Tape worm
4. Phylum Aschelminthes or Nemathelminthes
Phylum Aschelminthes consists of invertebrates having round and unsegmented body.
They are commonly known as roundworms.
Habitat
Most of the roundworms live as parasites and some are free living. They are found in
the intestine of animals. They suck blood of their host. However, some roundworms are
found in soil.
Salient features
a. The body is round, cylindrical and unsegmented.
b. Mouth and anus both are present. Do You Know
c. Both the ends of their body are pointed.
d. They are unisexual animals. The organism having only one type of sex
e. Their body is bilaterally symmertrical. organs (male or female) in its body is called
unisexual organism, e.g. round worm.
f. They reproduce sexually.
Examples: Roundowrm (Ascaris), Hookworm, Pinworm, etc.
16.16 Hookworm Pinworm
Roundworm (Ascaris)
GREEN Science (Biology) Book-9 265
5. Phylum Annelida
Phylum Annelida consists of invertebrates having many segmented rings in their bodies.
They are commonly known as annelids.
Habitat
They are found in water, soil and sand. Some of them are parasites (e.g. leech) and others
are free-living (e.g. earthworm).
Salient features Do You Know
a. Their body consists of numerous Leech sucks the blood of vertebrates
segmented rings. like human, cow, goat, etc. So, it is
called a parasite of vertebrates.
b. Their body is elongated, cylindrical and
segmented. Earthworm is found in soil. It is a free
living animal.
c. Their body is covered with soft and
moist skin (cuticle).
d. These animals may be unisexual or bisexual.
e. They breathe through skin.
f. They have nervous system, excretory system and circulatory system.
g. They are bilaterally symmetrical animals.
Examples: Earthworm, Leech, Sandworm, Nereis, etc.
Fig.
16.17 Leech Sandworm
Earthworm
6. Phylum Arthropoda
Phylum Arthropoda consists of invertebrates having jointed legs. They are commonly
known as arthropods.
Habitats Do You Know
Arthropods are found on land, air and water. Thorax is the middle part of an insect's
They are cosmopolitan invertebrates. body to which the wings and legs are
attached.
Salient features
a. Arthropods have jointed legs.
b. Their body can be divided into head, thorax and abdomen.
266 GREEN Science (Biology) Book-9
c. They have wings and legs for movement.
d. Their body is protected with a hard cover.
e. They breathe through skin, gills or trachea.
f. Their head contains a pair of antennae and compound eyes.
g. Insects have two pairs of wings.
h. They are unisexual animals.
Examples: Crab, Butterfly, Prawn, Grasshopper, Ant, Honeybee, Moth, Spider, Scorpion,
etc.
Fig. Fig.16.18 Prawn Butterfly Centipede
Crab
7. Phylum Mollusca
Phylum Mollusca consists of invertebrate animals having soft and unsegmented body.
They are commonly called molluscs.
Habitat
Molluscs are found in water and moist soil.
Salient features
a. Molluscs have soft and unsegmented body.
b. Their body is generally covered with one or two hard shells.
c. They breathe through gills or lungs.
d. They have a distinct head which contains tentacles, eyes and mouth.
e. Their body is asymmetrical.
f. They are unisexual animals.
g. They have digestive system, circulatory system and nervous system.
h. Their hard shell or cover is made of calcium carbonate.
Examples: Snail, Slug, Unio, Octopus, etc.
16.19 Slug Unio Octopus
Snail
GREEN Science (Biology) Book-9 267
8. Phylum Echinodermata
Phylum Echinodermata consists of marine invertebrates having spiny skin. They are
commonly known as echinoderms.
Habitat
Echinoderms are found only in marine water.
Salient features
a. Echinoderms have spiny skin.
b. Their body may be star-shaped (e.g. Starfish), globular (e.g. Sea urchin) or cylindrical
(e.g. Sea cucumber).
c. Distinct head is absent.
d. They move with the help of tube feet.
e. They are triploblastic animals.
f. Their body is radially symmetrical.
g. They reproduce sexually.
h. Mouth is present on the lower surface of the body.
Examples: Starfish, Sea cucumber, Sea urchin, Brittle star, etc.
Fig.
16.20 Sea cucumber Sea urchin Brittle star
Starfish
Vertebrates
We see a variety of animals in our surroundings like butterfly, frog, snake, lizard,
cockroach, grasshopper, snail, fish, bird, rabbit, rat, etc. Among them, frog, snake, lizard,
bird, rabbit and rat have backbones or vertebral columns. These animals are called
vertebrates. So, vertebrates can be defined as the animals having a backbone or vertebral
column. These animals have endoskeleton which forms the internal framework of the
body. The characteristics of vertebrates are given below:
a. They have a backbone or vertebral column.
b. They have bones in their bodies.
c. They may be cold-blooded or warm-blooded.
d. They have a well-developed blood circulatory system.
e. They have a well developed nervous system which consists of brain and spinal cord.
268 GREEN Science (Biology) Book-9
f. They move with the help of fins, limbs or wings.
Examples: Fish, Frog, Snake, Parrot, Bat, etc.
Fig.
16.21 Frog Snake Parrot
Fish
Phylum Chordata
The animals having notochord are kept in phylum chordata. The animals having notcohord
are called chordates. They develop gills in embryonic stage. They have a tubular nerve
cord just above the notochord. Their skeleton is covered with muscle. They have closed
blood vascular system.
Examples of chordates: Balanoglossus, Amphioxus, fish, frog, toad, bird, elephant, tiger,
horse, human beings, snake, etc.
Phylum chordata is further divided into four sub-phyla. They are:
1. Sub-phylum Hemichordata
2. Sub-phylum Urochordata
3. Sub-phylum Cephalochordata
4. Sub-phylum Vertebrata
In this unit, we will study about sub-phylum vertebrata only.
Different types of vertebrates are kept in sub-phylum vertebrata. It is further divided into
five classes.
1. Class Pisces
2. Class Amphibia
3. Class Reptilia
4. Class Aves
5. Class Mammalia
1. Class Pisces
Different types of fishes are grouped in Class Pisces. Fishes are cold-blooded aquatic
vertebrates having fins and gills. They cannot live on land. Some fishes are very small and
some are very big.
GREEN Science (Biology) Book-9 269
Characteristics
a. The body of fishes can be divided into head, trunk and tail.
b. They breathe through gills in water.
c. They move with the help of fins.
d. They are cold-blooded animals.
e. Their body is covered with smooth, slippery and water-proof scales.
f. They lay eggs in water.
g. Their heart is two-chambered.
h. They are unisexual.
Examples: Rohu, Sea horse, Carp, Shark, etc.
Fig.
16.22 Sea horse Carp Shark
Rohu
2. Class Amphibia
Different types of frogs, toads and salamanders are kept in Class Amphibia. These animals
can live in water as well as on land. The vertebrates that can live on land and in water are
called amphibians. They spend some part of life in water and rest on land.
Characteristics
a. The body of amphibians can be divided into head and trunk.
b. Their body is covered with smooth or rough skin.
c. Their skin is rich in glands.
d. They breathe through skin in water and through lungs on land.
e. They move with the help of limbs.
f. They are cold-blooded animals.
g. They lay eggs in water.
h. They are unisexual animals.
i. They have external fertilization.
j. They have three chambered heart.
Examples: Frog, Toad, Salamander, Hyla, etc.
270 GREEN Science (Biology) Book-9
Fig. Fig.16.23 Toad Salamander Hyla
Frog
Activity 1
Visit a nearby river or pond in your locality along with your science teacher.
Collect some fishes, frogs and their eggs.
Draw neat and labelled figures and write their salient features.
3. Class Reptilia
Different types of snakes, lizards and crocodiles are grouped in class Reptilia. These
animals crawl on ground. So, reptiles are crawling cold-blooded vertebrates. Most of
them live on land but some live in water. Reptiles are also called creepers or crawlers.
Characteristics
a. Reptiles creep or crawl on land.
b. Their body can be divided into head, neck, trunk and tail.
c. Their body is covered with hard and dry scales.
d. They move with the help of limbs but limbs are absent in snakes.
e. They breathe through lungs.
f. They lay eggs. The eggs have leathery shells.
g. Their heart is three-chambered.
h. They are unisexual animals.
i. They have internal fertilization.
Examples: Snake, Lizard, Tortoise, Crocodile, etc.
16.24 Lizard Tortoise Crocodile
Snake
GREEN Science (Biology) Book-9 271
4. Class Aves
Different types of birds are kept in Class Aves. Birds are the vertebrates that can fly in air.
They are found on land and in air.
Characteristics
a. Birds have feathers and wings. Fore limbs are modified into wings.
b. Their body can be divided into head, neck, trunk and tail.
c. They have very light bones and toothless beak.
d. They breathe through lungs.
e. They are warm-blooded animals.
f. They lay eggs.
g. They are unisexual animals.
h. They have air sacs in their bodies.
i. Their heart is four-chambered.
Examples: Crow, Hen, Sparrow, Peacock, Eagle, Penguin, Duck, Pigeon, Parrot, Kingfisher,
etc.
Fig.
16.25
Crow Sparrow Penguin Duck
5. Class Mammalia
Different types of vertebrates having mammary glands are grouped in Class Mammalia.
Mammals are warm-blooded vertebrates that directly give birth to their young ones and
suckle them. Most mammals live on land but some live in water.
Characteristics Do You Know
a. Mammals directly give birth to their Only mammals have mammary glands.
young ones and suckle them.
Bats are flying mammals.
b. Mammary glands or milk producing
glands are present. Whale and dolphin are aquatic
mammals.
c. Their body remains covered with hair.
Mammals have well developed brain.
d. They have a pair of external ears.
Human beings are the most developed
e. Their body can be divided into head, mammals.
neck, trunk and tail.
f. They breathe through lungs.
272 GREEN Science (Biology) Book-9
g. They are warm-blooded animals.
h. They move with the help of fins, limbs or wings.
Examples: Cow, Dog, Cat, Elephant, Rhinoceros, Bat, Dolphin, Whale, Lion, Zebra,
Monkey, Rabbit, Tiger, etc.
Fig.
16.26 Elephant Dolphin Tiger
Cow
Project work
Observe different types of vertebrates in your locality.
Study their characteristics and write in your project work notebook.
Draw a neat and labelled figure of each.
Name the class of each of the vertebrates.
Kingdom Animalia
1. Phylum Porifera
2. Phylum Coelenterata
3. Phylum Platytelminthes
4. PhylumNemathelminthes
5. Phylum Annelida
6. Phylum Arthropoda
7. Phylum Mollusca
8. Phylum Echinodermata
Hemichordata 9. Phylum Chordata
Sub-phylum
Urochordata Cephalochordata Vertebrata
Class
Pisces Amphibia Reptilia Aves Mammalia
GREEN Science (Biology) Book-9 273
Classification of some Animals
1. Sea anemone
Kingdom : Animalia Fig. Fig. Fig. Fig.
Coelenterata
Phylum : Sea anemone
Type : 16.26
16.27
2. Earthworm Animalia 16.28
Annelida 16.29
Kingdom : Earthworm 16.30
Phylum : 16.31
Type :
3. Sea cucumber
Kingdom : Aninalia
Phylum : Echinodermata
Type : Sea cucumber
4. Sea horse Animalia
Chordata
Kingdom : Vertebrata
Pisces
Phylum : Sea horse
Sub-phylum :
Class :
Type :
5. Peacock Animalia
Chordata
Kingdom : Vertebrata
Aves
Phylum : Peacock
Sub-phylum : Fig.
Class :
Type :
6. Elephant Animalia
Chordata
Kingdom : Vertebrata
Mammalia
Phylum : Elephant
Sub-phylum : Fig.
Class :
Type :
274 GREEN Science (Biology) Book-9
Mosquito
Mosquitoes are harmful insects that belong to class Insecta of phylum Arthropoda. They
not only suck blood from humans and other vertebrates but also transmit various diseases
like malaria, filariasis, encephalitis, dengue, yellow fever, etc. from infected person to
another. Therefore, mosquitoes are considered harmful insects. Nearly about 3000 species
of mosquitoes are found throughout the world. Among them, about 100 species of
mosquitoes transmit various diseases. Culex, Anopheles and Aedes are the most common
species of mosquitoes found throughout tropical and sub-tropical regions. Now-a-days,
mosquitoes are found in high altitudes like Namchebazar of Solukhumbu district due to
effect of climate change.
Mosquitoes become active during night. So they are called nocturnal animals. They are found
in damp and marshy places of tropical and sub-tropical countries. Female mosquitoes suck
blood from humans and other vertebrates but male mosquitoes do not suck blood. They
live on nectar of plants. Because of blood-sucking habit, female mosquitoes are medically
important than males. Because female mosquitoes are the vectors of various diseases like
malaria, encephalitis, meningitis, dengue, yellow fever, filariasis, etc. Generally, mosquitoes
live in dark place and corners of room, bushes, etc. Mosquitoes lay eggs in water where they
complete their life cycle.
Fig.16.32Female Anopheles mosquito Female Aedes mosquito
Fig. Female Culex mosquito
External Structure of Mosquito
The body of an adult mosquito can Thorax Abdomen
be divided into three distinct parts. Head
They are head, thorax and abdomen.
The body is small, slender and about
3-4 mm long. The grayish-black
body of mosquito remains covered
with tiny scales.
The head is small and spherical
in shape. It consists of a pair of 16.33
compound eyes, a pair of jointed
External structure of Mosquito
antennae and piercing and sucking
type of mouthparts. The mouthparts of mosquito consists of a needle-like proboscis
which is used for sucking blood.
GREEN Science (Biology) Book-9 275
The middle part of the body is called thorax. It can be divided into three parts, viz.
prothorax, mesothorax and metathorax. Each part of thorax consists of a pair of long
jointed legs. The mesothorax consists of a pair thin, narrow and membranous wings. The
wings of female mosquitoes are larger than that of male mosquitoes. The metathorax
consists of a pair of rudimentary wings called halters or balancers which vibrate and
produce characteristic sound of mosquito.
Compound eye
Antennae
Labrum
Mandibles
Maxillae
Fig. Hypopharynx Maxillary palpi
Fig. Labium
16.34
Mouth parts of mosquito
The abdomen of mosquito is small and cylindrical. It consists of nine segments. The ninth
abdominal segment contains anus.
Life cycle
Mosquitoes show complete metamorphosis in their life cycle. It means that the life cycle
of mosquito completes in four distinct stages. They are (i) Egg (ii) Larva (iii) Pupa and (iv)
Adult.
Larva
Eggs
Pupa
16.35 Adult
Life cycle of Anopheles mosquito
276 GREEN Science (Biology) Book-9
Mosquitoes are found in gardens, crop-fields, near sewage, etc. but they need water to
reproduce. Out of four stages of the life cycle, first three stages, i.e. egg, larva and pupa
develop in water.
In mosquitoes, mating takes place in air while flying. The female mosquito takes a blood
meal after mating and then lays eggs in stagnant water of puddles, ditches, pools, etc.
1. Egg
After mating, a female mosquito lays eggs in water. Some mosquitoes lay eggs in clean
water and others lay in dirty water. A female Anopheles mosquito lays 40 - 100 eggs at a
time in clean resting water. The eggs contain lateral air floats and are laid separately. A
female Culex mosquito lays 200-400 eggs at a time in dirty water. The eggs are narrow
and elongated without air floats. The eggs of Culex mosquito are cigar-shaped. Which
remain attached together forming a raft. The raft floats on water like a boat.
Lateral air
floats
Fig. Eggs laid singly on the A boat or barrel Eggs laid in a cluster on water Cigar shaped
shaped egg surface egg
water surface
16.36
Eggs of Anopheles Larva of Culex
Differences between eggs of Anopheles and eggs of Culex mosquito
Eggs of Anopheles Eggs of Culex
1. They are boat-shaped. 1. They are cigar-shaped
2. They have lateral air floats. 2. They do not have lateral air floats.
3. They are laid separately. 3. They are laid in a group.
4. They are found in clean water. 4. They are found in dirty water.
2. Larva
Larva is the second stage of life cycle. On favourable condition, the egg hatches into a tiny
larva within 2 - 3 days. The larva is small and transparent. The larva of a mosquito moves
in water by wriggling movement. Therefore, it is called a wriggler.
The body of a larva can be divided into head, thorax and abdomen. The head consists of a
pair of compound eyes, a pair of antennae and chewing types of mouthparts. The thorax
of larva is wider than the head. It consists of three pairs of lateral tufts of hairs. Legs are
absent in thorax.
GREEN Science (Biology) Book-9 277
The abdomen of larva is Adult
elongated having nine-
segments. A respiratory siphon Adult Eggs
is present on the 8th segment emerges
and four tracheal gills are
attatched to the 9th segment.
Each abdominal segment bears
a pair of bristles.
When at rest, the larva of Larva
Anopheles remains parallel
to the surface of water but the
larva of Culex hangs with its
head downwards at an angle of
45° to the surface of water.
Fig.
Fig.The respiratory siphon of the Pupa
larva of Anopheles is shorter Life cycle of Culex Mosquito
than that of Culex. The larva of 16.37
mosquito moults 3-4 times. At
the last moult, the larva changes
into a pupa within two weeks.
Water Spiracle
surface
Water surface Breathing
Compound eye siphon
Feeding
brushes
Head
Head Thorax Hair tuft
Antenna Tracheal gills
Thorax
16.38 Compound eye
Larva of Anopheles Antenna
Larva of Culex
Differences between larva of Anopheles and larva of Culex mosquito
Larva of Anopheles Larva of Culex
1. It is a surface feeder. 1. It is a bottom feeder.
2. Its respiratory siphon is shorter and 2. Its respiratory siphon is longer and
wider. narrower.
3. While resting, it remains parallel to the 3. While resting, it makes an angle of
surface of water. 45° to the surface of water.
278 GREEN Science (Biology) Book-9
3. Pupa
Pupa is the third stage of the life cycle. On favourable condition, each larva developes into
a comma-shaped pupa withing two weeks. The body of a pupa can be divided into two
parts, viz. cephalothorax and abdomen. The cephalothorax is the fused form of head and
thorax. It consists of a pair of compound eyes, a pair of antennae and a pair of respiratory
trumpets. The abdomen is nine segmented and the last abdominal segment consists of a
pair of large swimming paddles.
Unlike other insects' pupae, the pupa of a mosquito is quite active. It swims actively
in water. The pupa does not eat as there is no mouth but breathes through respiratory
trumpets. The pupa changes into an imago within 2 – 7 days on favourable condition.
Respiratory trumpet Respiratory trumpet Water surface
Water surface
Cephalothorax Cephalothorax
Antenna Antenna
Compound eye Compound eye
16.39Fig. Fig. Pupa of Culex
Pupa of Anopheles
Differences between pupa of Anopheles and Pupa of Culex
Pupa of Anopheles Pupa of Culex
1. It is green in colour. 1. It is colourless.
2. Its head is small. 2. Its head is large.
3. Respiratory siphons are shorter. 3. Respiratory siphons are longer.
4. Imago
On favourable condition, each pupa changes into an imago within 2 - 7 days. A newly
emerged adult is called an imago. The imago emerges out by tearing the puparium, i.e.
cover of pupa. The imago dries its wings for sometime before flying.
16.40 Adult of Culex
Adult of Anopheles
GREEN Science (Biology) Book-9 279
In this way, the life cycle of mosquito is completed.
Differences between adult of Anopheles and adult of Culex mosquito
Adult of Anopheles Adult of Culex
1. It makes an acute angle to the surface 1. It remains parallel to the surface of
while resting. water while resting.
2. Palpi are shorter than proboscis. 2. Palpi and proboscis both are equal in
length.
3. Wings are transparent. 3. Wings are spotted.
4. It cannot fly for long. 4. It can fly for long.
Disadvantages of Mosquitoes
Mosquitoes are harmful insects for human beings and other animals. Because they bite
and transmit various diseases like malaria, yellow fever, dengue, meningitis, filariasis,
encephalitis etc. Some common diseases transmitted by mosquitoes with their causative
agent are given below:
Diseases Types of mosquito Causative agent
1. Malaria Female Anopheles Plasmodium
2. Yellow fever Female Aedes Virus
3. Filariasis Female Culex Wuchereria bancrofti
4. Encephalitis Female Culex Virus
5. Dengue Female Aedes Virus
Female Culex
Female Aedes
Malaria
Malaria is the most common disease transmitted by mosquito. It is transmitted by female
Anopheles mosquito and caused by a protozoan parasite called Plasmodium. This disease
is common in tropical and sub-tropical regions.
When a female Anopheles mosquito bites a person suffering from malaria, it sucks
numerous Plasmodium parasites along with blood. These parasites complete a part of
their life cycle in the body wall of mosquito and finally come in the salivary gland of
the mosquito. When the mosquito containing infective stages of Plasmodium in salivary
gland, bites a healthy person, the person acquires infection. Then these parasites enter
the liver through blood stream and complete a part of their life cycle and finally infect
red blood cells. The symptoms of malaria occur when Plasmodium parasites infect and
destroy red blood cells.
280 GREEN Science (Biology) Book-9
Prevention of infection
1. We should sleep inside the net to avoid mosquito bite.
2. We should spray insecticides to kill adult mosquitoes inside the houses.
3. We can drive mosquitoes away by burning mosquito coils.
4. We should fill the puddles, ditches, etc. with sand or soil to control the breeding of
mosquitoes.
5. We can kill mosquito larvae and pupae by spraying kerosene, paraffin etc. in the
surface of water containing mosquito larvae and pupae.
6. We should introduce larvivorous fishes like trout, Gambusia, Tilapia, etc. to control
mosquito larvae and pupae.
Key Concepts
1. The grouping of living organisms on the basis of similarities and differences is
called classification. It makes the study of living organisms easy and systematic.
2. Microscopic organisms having prokaryotic cell are kept in Kingdom Monera. The
organisms of this kingdom are unicellular having DNA (deoxyribonucleic acid) as
a nucleus.
3. Unicellular organisms having eukaryotic cells are kept in Kingdom Protista.
4. Kingdom Protista includes unicellular animals like amoeba, paramecium, euglena,
trypanosoma, trichomonas, etc.
5. Unicellular and multicellular organisms without chlorophyll are kept in Kingdom
Fungi.
6. Non-green plants like mushroom, yeast, mucor, Penicillim, etc. belong to Kingdom
Fungi.
7. Different types of non-flowering plants and flowering plants are kept in Kingdom
Plantae. They have chlorophyll.
8. The plants which do not bear flowers are called non-flowering plants. They are also
called cryptogams.
9. The plants which bear flowers and seeds are called flowering plants. They are more
developed than non-flowering plants.
10. Bryophytes grow on moist and they need water to reproduce. Therefore, bryophytes
are also called amphibian plants.
11. Well developed plants having vascular tissues are kept in division Tracheophyta.
These plants may be non-flowering or flowering.
12. Sub-division Pteridophyta consists of well developed cryptogams having feather-
shaped leaves.
13. Sub-division Gymnosperms consists of cone bearing plants having naked seeds.
14. Sub-division Angiosperms consists of the most developed flowering plants having
fruits. They are found on land and in water.
15. Class monocot includes flowering plants having only one cotyledon in their seeds.
GREEN Science (Biology) Book-9 281
16. Class dicot includes well developed flowering plants having two cotyledons in
their seeds.
17. Invertebrates are those animals which do not have backbone or vertebral column.
Examples: Amoeba, sponge, hydra, tapeworm, roundworm, earthworm, butterfly,
snail, starfish, etc.
18. Phylum Porifera consists of primitive multicellular animals having numerous pores
in their bodies.
19. Phylum Platyhelminthes consists of invertebrates having flat body. These animals
are commonly known as flatworms.
20. The animals having male and female reproductive organs in the same body are
called bisexual animals, e.g. tape worm, liver fluke, etc.
21. Phylum Aschelminthes consists of invertebrates having round and unsegmented
body. They are commonly known as roundworms.
22. Phylum Annelida consists of invertebrates having many segmented rings in their
bodies. They are commonly known as annelids.
23. Phylum Arthropoda consists of invertebrates having jointed legs. They are
commonly known as arthropods.
24. Phylum Mollusca consists of invertebrate animals having soft and unsegmented
body. They are commonly called molluscs.
25. Phylum Echinodermata consists of marine invertebrates having spiny skin. They
are commonly known as echinoderms.
26. Vertebrates can be defined as the animals having a backbone or vertebral column.
These animals have endoskeleton which forms the internal framework of the body.
27. The animals having notochord are kept in phylum chordata. The animals having
notochord are called chordates.
28. Fishes are cold-blooded aquatic vertebrates having fins and gills.
29. The vertebrates that can live on land and in water are called amphibians.
30. Reptiles are crawling cold-blooded vertebrates. Most of them live on land but some
live in water.
31. Birds are the warm-blooded vertebrates that can fly in air.
32. Mammals are warm-blooded vertebrates that directly give birth to their young ones
and suckle them.
33. Mosquitoes are harmful insects that belong to class Insecta of phylum Arthropoda.
They not only suck blood from humans and other vertebrates but also transmit
various diseases like malaria, filariasis, encephalitis, dengue, yellow fever, etc. from
infected person to another. Therefore mosquitoes are considered harmful insects.
34. Mosquitoes become active during night. So they are called nocturnal animals. They
are found in damp and marshy places of tropical and sub-tropical countries.
282 GREEN Science (Biology) Book-9
35. The body of an adult mosquito can be divided into three distinct parts.
36. Mosquitoes show complete metamorphosis in their life cycle. It means that the life
cycle of mosquito completes in four distinct stages. They are (i) Egg (ii) Larva (iii)
Pupa and (iv) Adult.
37. Malaria is the most common disease transmitted by mosquitoes. It is transmitted by
female Anopheles mosquito and caused by a protozoan parasite Plasmodium.
Sequential General Exercise 1
1. Choose the best answer from the given alternatives.
a. Chlorophyll is absent in ....................................
spirogyra mushroom
moss fern
b. Which of the following plant belongs to sub-division gymnosperms?
cycas rose
lycopodium mustard
c. The animals having numerous pores in their bodies are kept in phylum .................
chordata arthropoda
porifera coelenterata
d. Which of the following animals belongs to class reptilia?
sea horse horse
crocodile peacock
e. The life cycle of mosquito completes in ............................. stages.
one two
three four
GREEN Science (Biology) Book-9 283
2. Answer the following questions.
a. What is classification?
b. Name any two organisms that belong to Kingdom Monera.
c. Name the scientist who propounded five kingdom system of classification.
d. Write any three salient features of the plants that belong to division.
(i) Algae (ii) Bryophyta (iii) Tracheophyta
e. What are invertebrates ? Name eight phyla of invertebrates.
f. What are coelenterates? Write their three characteristics.
g. Write any three salient features of the animals that belong to phylum
i. Annelida ii. Arthropoda
iii. Mollusca iv. Chordata
h. What are vertebrates? Give any five examples.
i. Write any three salient features of the animals that belong to class:
i. Pisces ii. Reptilia iii. Mammalia
j. Where are mosquitoes found? Why are they considered harmful insects?
k. Name any three diseases transmitted by mosquitoes.
l. How is malaria transmitted from one person to another? Describe.
m. How can we control mosquitoes? Write any three points.
3. Classify the given organisms with any two salient features of each:
a. Moss b. Spirogyra c. Fern d. Pea
e. Cycas f. Bamboo g. Maize h. Bean
i. Apple j. Rohu k. Sea horse l. Lizard
m. Crow n. Bat o. Snake p. Dolphin
4. Differentiate between
a. Algae and Fungi
b. Gymnosperms and Angiosperms
c. Monocot and Dicot
d. Fish and Frog
e. Roundworm and Tapeworm
f. Bat and Bird
g. Larva of Culex and Larva of Anopheles
h. Adult Culex and Adult Anopheles
5. Give reason.
a. Fern and cycas are kept in division tracheophyta.
b. Fish is kept in phylum chordata.
c. Bat is kept in class mammalia.
d. Mosquitoes are considered harmful insects.
6. Draw a neat and labelled figure showing the life cycle of Anopheles mosquito.
284 GREEN Science (Biology) Book-9
Grid-based Exercise 2
Group ‘A’ (Knowledge Type Questions) (1 Mark Each)
1. What is classification ?
2. What is binomial system of nomenclature?
3. What types of plants are called thalloid?
4. What do you mean by rhizoids?
5. What types of plants are kept in the sub-division pteridophyta?
6. Which type of animals are called invertebrates ?
7. Which type of animals are kept in metazoa?
8. Write any two functions of tentacles found in hydra.
9. What type of animals are called hermaphrodite animals?
10. Write down two characteristics of the animals belonging to the phylum Chordata.
11. What are warm-blooded animals ?
12. What are mammals?
13. Which mosquito transmits malaria? Write.
14. Name a disease transmitted by the adult Anopheles.
15. What type of climate is suitable for mosquitoes? Write.
For Group ’B’ (Understanding Type Questions) (2 Marks Each)
16. Why is Carolus Linnaeus considered as the father of taxonomy? Give reason.
17. Volvox is kept in the division Algae and moss is kept in division bryophyta, why ?
Give reason.
18. Fern is considered as the most developed plant among cryptogams, why ? Give any
two reasons.
19. Write any two differences between jelly fish and starfish.
20. The body of tapeworm is segmented but that of liverfluke is unsegmented. However,
both of them are kept in the same phylum. Give reason.
21. Sea horse is kept in class pisces and horse is kept in class mammalia, why ?
22. Write any two differences between bird and bat.
23. Female mosquito is considered more harmful than the male mosquito, why ?
24. Write any two differences between Culex and Anopheles mosquito.
25. Larvae of mosquito die when kerosene is sprayed on the surface of the pond containing
mosquito larvae, why?
26. It is more beneficial to know about the life cycle of a mosquito to control them, why?
27. Malaria can be controlled by controlling mosquitoes. Give suitable reason.
For Group ‘C’ (Application Type Questions) (3 Marks Each)
28. What is the advantage of classification of living beings? Write in any three points.
29. Write down two characteristics of the living beings belonging to kingdom Monera
with any two examples.
30. Write down two characteristics of the plants belonging to division bryophyta and
write any two examples
GREEN Science (Biology) Book-9 285
31. Write down two salient features of the plants belonging to division Gymnosperms
with any two examples
32. Name the phylum of the given animals. Also write a characteristic of each.
i. ii. iii.
33. How can we control mosquitoes? Write any three ways.
34. How can we control mosquitoes by filling puddles? What should be done to avoid
mosquito bite while working in farms?
35. Write any three methods to control mosquito larvae and pupae.
36. Draw a neat and labelled figure showing the life cycle of Culex mosquito.
For Group ‘D’ (Higher Abilities Type Questions) (4 Marks Each)
37. Classify the animal shown in the figure and write any two characteristics.
i. ii.
38. Write any two differences between fish and frog on the basis of habitat and structure
of heart. Name the phylum of the animals having following features.
i. Having segmented body, hermaphrodite
ii. Moves with the help of tentacles, found in marine water
iii. Having sucker, flat and segmented body
iv. Soft body with a hard cover, having tentacles
39. What types of animals are called mammals ? Write down three characteristics of these
animals.
40. Classify given animals with a characteristic of each:
i. Snake ii. Fern
41. Name the class of the animals having given features. Also, give an example of each.
i. Breathe through gills, having scales
ii. Having external ears, give birth directly to young ones
iii. Having webbed feet, live on both land and in water
iv. Fly in air, lay eggs
42. What should be done to avoid mosquito bite ? Write any two methods. Differentiate
between Culex mosquito and Anopheles mosquito in any two points on the basis of
egg-laying habit and structure.
43. Describe the life cycle of Anopheles mosquito with a neat figure.
286 GREEN Science (Biology) Book-9
UNIT Adaptation of
17 Organisms
Weighting Distribution Theory : 5 Practical: 1
Before You Begin
A fish can breathe in water. But when it is taken out of water, it dies.
The fish has gills adapted to breathe only in water. A fish cannot
breathe on land through gills and it dies. On the other hand, we can
breathe on land through lungs but cannot breathe inside water through
lungs. The lungs are not adapted to breathe in water. The ability of an
organism to adjust itself in its habitat is called adaptation. It includes
structural, functional and behavioural modifications which make
an organism better fitted in its habitat. The special characteristics of
an organism due to which the organism can adjust in its habitat are
called adaptational characteristics. Sharp and pointed claws in tiger,
feathers in birds, fleshy stem in cactus, webbed feet in frog, etc. are the
examples of adaptational characteristics. In this unit, we will study
adaptational characteristics of plants and animals, and microscopic
organisms like virus, bacteria, fungi and protozoa in brief.
Learning Objectives Syllabus
After completing the study of this unit, students will be able to: • Introduction to adaptation
i. introduce adaptation with examples. • Adaptational characteristics of
ii. list different types of aquatic and terrestrial plants and animals
organisms. • Microscopic organisms
iii. explain the adaptational characteristics of plants and - Bacteria
animals with examples. - Fungi
- Virus
iv. introduce some microscopic organisms (viruses, - Protozoa
bacteria, fungi and protozoa) and list human diseases
caused by them.
Glossary: A dictionary of scientific/technical terms
adaptation : the ability of an organism to adjust in its environment
xerophytes : the plants that grow in desert
hydrophytes : the plants that grow in water
viruses : the sub-microscopic particles that show properties of both living beings
fungi and non-living things
: non-green plants without chlorophyll
GREEN Science (Biology) Book-9 287
Adaptation
In our surroundings, different types of plants and animals are found. Some of them live
in water whereas others live on land. These organisms may be microscopic (like amoeba,
paramecium, bacteria, etc.) to very large in size (like trees, elephant, blue whale, etc.). All
kinds of plants and animals have special characteristics in their bodies due to which they
can adapt in their habitat. These characteristics are called adaptational characteristics.
Similarly, the ability of an organism to adjust itself in its habitat is called adaptation. A fish
can adapt in water but cannot adapt on land. On the other hand, a cow can adapt on land
but cannot adapt in water. If living beings cannot adapt in their habitat, they disappear. In
this unit, we will study about adaptational characteristics of plants and animals.
Aquatic adaptation
A variety of plants and animals live in water. The animals that live in water are called
aquatic animals. Examples, fish, dolphin, octopus, etc. The plants that live in water are
called aquatic plants. They are also called hydrophytes. Aquatic plants and animals have
ability to get food and respiratory gases from water.
Hydrophytes
The plants that live in water are called hydrophytes. They are divided into following
three types.
1. Floating hydrophytes
2. Submerged hydrophytes
3. Fixed and emergent hydrophytes
1. Floating hydrophytes
The hydrophytes that float freely in water are called floating hydrophytes. Their roots
are not attached to the soil.
Example : Lemna, Pistia, Wolfia, etc.
Fig.
17.1 Pistia Wolfia
Lemna
2. Submerged hydrophytes
The hydrophytes that remain immersed in water are called submerged hydrohytes.
Their roots are attached to the soil.
288 GREEN Science (Biology) Book-9
Examples : Hydrilla, vallisneria, etc.
Fig. Fig.17.2 Vallisneria
Hydrilla
3. Fixed and emergent hydrophytes
Some hydropytes have roots fixed to the soil but their stem and leaves emerge out of
water. Such type of hydrophytes are called fixed and emergent hydrophytes. They
have developed roots attached to the soil.
Examples: Ranunculus, Sagittaria, Typha, Lotus, Rumex, etc.
17.3 Sagittaria Typha Lotus
Ranunculus
Adaptational Characteristics of Hydrophytes
1. Aquatic plants (hydrophytes) have very less developed root system. Some
hydrophytes do not have roots.
2. Hydrophytes have long, soft and spongy stem.
3. The body of hydrophytes remains covered with waxy substance. It prevents them
form decaying in water.
4. Floating hydrophytes have air filled sacs which help them to float in water.
5. The leaves of submerged hydrophytes (e.g. hydrilla) are narrow and thin.
6. The leaves of floating and emergent hydrophytes are broad and large.
7. Hydrophytes have less develop xylem and phloem tissues.
GREEN Science (Biology) Book-9 289
Aquatic animals
The animals that live in water are called aquatic animals. Fish, octopus, dolphin, shark,
eel, etc. are some common examples of aquatic animals.
Fig.17.4 Octopus Shark Dolphin
Fig. Fish
Adaptational characteristics of aquatic animals
1. Aquatic animals have boat-shaped or streamlined body which helps them to swim in
water.
2. Aquatic animals have pointed head, smooth body and powerful tail. These features
help them to swim easily in water.
3. The body of aquatic animals consists of air filled sacs which help them to float in
water.
Spiny dorsal fin Soft dorsal fin
Spinal cord Gallbladder Caudal fin
Swim bladder
Brain Kidney
Lateral line
Gills
Heart Liver Intestine Bladder Anal
Esophagus Pancreas Anus fin
Pelvic fin Stomach Reproductive
17.5 organ
Structure of a fish
4. Aquatic animals have ability to adjust body temperature according to the temperature
of their surroundings. So they can survive in cold and hot environment.
5. Aquatic animals have fins and tail to help them to swim in water they also help them
to change to direction in water.
6. Most aquatic animals have gills adapted to breathe in water.
7. The body of aquatic animals remains covered with water. proof scales or mucous coat
which prevents the body from decaying.
290 GREEN Science (Biology) Book-9
Terrestrial adaptation
Different types of plants and animals are found on land. The organisms that live on land
are called terrestrial organisms. They obtain food, respiratory gas (oxygen) and shelter
from land. Terrestrial organisms are divided into terrestrials plants and terrestrial animals.
Adaptational characteristics of terrestrial plants
The plants that live on land are called terrestrial plants. Mango, rose, apple, cactus, Aloe
vera etc. are some examples of terrestrial plants. The major adaptational characteristics of
terrestrial plants are given below:
1. Terrestrial plants have strong and well developed root system.
2. Climber plants like cucumber, gourd, pumpkin, etc. have tendrils, hooks and aerial
roots for support.
3. Mesophytes have well developed vascular tissues.
4. Xerophytes like cactus, aloe vera, opuntia, etc have long and well developed root
system adapted to absorb maximum water from the soil.
Fig. Fig.17.6 Opuntia Aloe vera
Cactus
5. Desert plants are stunted and having thick barks.
6. The leaves of xerophytes are reduced into thorns to reduce the loss of water through
transpiration.
7. Desert plants have thick and fleshy stem modified to store water.
Adaptational characteristics of terrestrial animals
The animals that live on land are called terrestrial animals. Cow, goat, tiger, lion, horse,
giraffe, monkey, squirrel, camel, etc. are some examples of terrestrial animals. Different
types of reptiles, birds and mammals live on land.
17.7 Lion Horse
Tiger
GREEN Science (Biology) Book-9 291
The major adaptational characteristics of terrestrial animals are given below:
1. The limbs of terrestrial animals are modified according to their habit and habitat.
They have long and strong legs adapted for walking, jumping, etc.
Some animals like zebra, horse, donkey, etc. have non-lobed hoof whereas animals
like cow, buffalo, sheep, goat, etc. have bilobed hoof.
Fig.17.8Cow
Fig. Fig. Zebra
2. Birds are adapted for aerial mode
of life. They have streamlined body
adapted for reducing air resistance
while flying. Their fore limbs are
modified in the form of wings for
flying.
They have light bones and toothless Peacock
beak to reduce the body weight.
Numerous air-sacs are found in the
body which help them to fly easily. 17.9
The beaks of birds are also modified
according to their feeding habit.
The beaks of birds are also modified according to their feeding habit.
17.10
Beak of vulture Beak of duck Beak of woodpecker
Beak of a vulture is pointed and curved adapted for tearing flesh. Duck has a spoon-
shaped beak adapted fro searching insects. Woodpecker has a long and strong beak
adapted for boring into wood. Different types of birds gave different types of claws
292 GREEN Science (Biology) Book-9
modified according to their habit and habitat. For example, birds like eagle, hawk,
etc. have sharp and pointed claws adapted for grasping their prey. Ducks have
webbed feet adapted for swimming in water.
3. Desert animals (like camel) have special tissues
adapted for storing water. They have thick skin
to prevent loss of water through perspiration.
They have a hump on their back to store food
in the form of fat.
17.11
Fig. Fig. Fig.
Fig. Camel
4. Animals like house-wall-lizards have adhesive
pads on their digits. They are adapted to climb
on walls without falling downwards.
17.12
Adhesive pads of housewall lizard
5. Climbing animals like monkeys have strong
muscles and limbs with long digits adapted for
jumping, climbing and holding tree branches.
17.13
A monkey is climbing a tree
6. Burrowing animals like mole, rabbit, rat, etc. have pointed snout. They have strong
fore limbed with pointed digits adapted for making burrows.
17.14 Rabbit
Mole
GREEN Science (Biology) Book-9 293
Bacteria
Bacteria are the most primitive, unicellular and microscopic plant organisms. They are
the simplest living organisms. Bacteria are found in air, water, soil and inside the body of
plants and animals. They can be found in almost all parts of the earth.
Fig.17.15 Do You Know
Fig. Bacteria
In 1676 AD, Anton Van Leeuwenhoek
discovered bacteria but the term
"bacteria" was coined by CG Ehrenberg
in 1828 AD.
The singular of bacteria is bacterium.
Some bacteria can survive in boiling
water and some can survive in ice.
Most bacteria do not have chlorophyll and only a few have chlorophyll. It means most
bacteria are saprophytes and only a few are autotrophs.
Structure of Bacteria Capsule
Cell wall
Bacteria have a very simple Plasma membrane
cellular structure. The cell
of bacteria consists of a non- Cytoplasm
living cell wall and a thin Ribosomes
living membrane called Plasmid
plasma membrane.
Pili
The cell of a bacterium
consists of protoplasm and Bacterial Flagellum
genetic material, i.e. DNA. Nucleoid (Circular DNA)
Some bacteria contain 17.16
flagella. Membrane bound Structure of bacterium
structures like mitochondria,
golgi bodies, etc. are absent in bacteria. The cell of bacteria is called prokaryotic cell as it
has a primitive nucleus.
Characteristics of Bacteria
1. They do not have a well developed nucleus.
2. Their size ranges from 0.5 to 5 micrometers.
3. A cell wall is present in them.
4. The mode of nutrition may be heterotrophic or autotrophic.
5. Most bacteria are immotile but some bacteria like spirilla and bacilli are motile.
6. They may live alone or in colonies.
7. They reproduce asexually by fission.
294 GREEN Science (Biology) Book-9
Types of Bacteria
There are four types of bacteria on the basis of shape. They are:
i. Spherical bacteria or coccus, e.g. Diplococci, etc.
ii. Spiral bacteria, e.g. spirillum, leptospira, etc.
iii. Rod-shaped bacteria or Bacillus, e.g. Escherichia coli
iv. Comma-shaped bacteria or Vibrio, e.g. Vibrio cholera
Fig.
17.17 Spirillum bacteria Bacilli bacteria Vibrio bacteria
Cocci bacteria
Advantages of Bacteria
1. Some bacteria like Rhizobium increase the fertility of soil by regulating nitrogen
cycle.
2. Bacteria are used for making medicines like antibiotics.
3. Many bacteria help in digestion of food.
4. Bacteria act on dead bodies and decompose them which helps in recycling of materials
in the environment.
5. Bacteria are used in tanning of leather, curding of milk, cheese making and processing
of tobacco, coffee, etc.
Disadvantages of Bacteria Do You Know
1. Bacteria cause diseases in plants and Bacteria cause various diseases in
animals. human beings like typhoid, leprosy,
scrub typhus, pneumonia, dysentery,
2. Some bacteria like Pseudomonas decrease tetanus, tuberculosis, etc.
the fertility of soil.
3. Bacteria spoil food, milk, vegetables, fruits, etc.
4. Some bacteria release toxins into food and cause food poisoning.
Viruses
Viruses are sub-microscopic, obligatory parasites that cause various diseases in plants
and animals. The word 'virus' has been derived from a Latin word 'venom' which
means poison or poisonous fluid. The size of viruses ranges from 25 nanometers to 250
nanometers. They are about 50 times smaller than bacteria. Viruses can only be seen under
an electron microscope.
GREEN Science (Biology) Book-9 295
Fig.17.18Retro virus (HIV)TMV (Tobacco Mosaic Virus)
Fig. Flu virus
Viruses do not have nucleus and cytoplasm. It means that they do not have a cellular
structure. Some viruses contain DNA (Deoxyribonucleic acid) and others contain RNA
(Ribonucleic acid). Viruses cause various diseases in plants and animals. Mosaic disease
of tobacco, cabbage, mustard; black ring spot of cabbage, leaf roll of tomato, etc. are the
viral diseases found in plants. Similarly, common cold, AIDS, rabies, polio, measles,
chicken pox, meningitis, etc. are the viral diseases common in human beings.
Viruses have different shapes like hexagonal, cylindrical, spherical, etc. The genetic
material, i.e. DNA or RNA of a virus remains surrounded by a coat of protein called
capsid. Viruses show the properties of both non-living things and living beings. Therefore,
they are kept in the borderline of living beings and non-living things.
Non-living properties of viruses
1. Viruses do not have a cellular structure.
2. They do not perform metabolic activities.
3. They can be crystallized like non-living things.
Living properties of viruses
1. Viruses contain genetic material, i.e. either DNA or RNA.
2. They reproduce in a large number inside the host cell.
3. They transmit hereditary characteristics to their offspring.
Types of viruses
On the basis of type of host, there are three types if viruses. They are:
1. Plant viruses 2. Animal viruses 3. Bacteriophages
1. Plant viruses
The viruses that attack plants are called plant viruses,
e.g. tobacco mosaic virus (TMV). It is a rod shaped
RNA virus that attacks the leaves of tobacco.
17.19
TMV virus
296 GREEN Science (Biology) Book-9
2. Animal viruses Fig. Fig.
The viruses that attack animals are called animal
viruses, e.g. retro virus (HIV), polio virus, flu virus,
paramyxo virus, rhino virus, etc.
17.20
Rhino virus
3. Bacteriophages
The virus that attacks bacteria is called bacteriophage
virus. It consists of two parts, i.e. head and tail. The
head is hexagonal which remains covered with a
protein coat called capsid. The tail is cylindrical and 17.21
consists of tail fibres.
Bacteriophage
Modes of transmission of viruses
1. Through air, water and food
2. Direct contact with infected organism
3. Through droplets while coughing and sneezing
4. From infected mother to unborn/newly born baby
5. Through vectors like mosquito, houseflies, etc.
Differences between Viruses and Bacteria
Viruses Bacteria
1. They do not show metabolic activities. 1. They show metabolic activities.
2. They are acellular particles. 2. The are living cellular organisms.
3. Cell wall is absent. 3. Cell wall is present.
Fungi Do You Know
Fungi are plants without chlorophyll. They Fungi cannot prepare their own food
may be unicellular (yeast) or multicellular due to absence of chlorophyll and
(mushroom). They cannot prepare their own depend on dead and decaying organic
food. So, they depend on dead and decaying matter for food. Therefore, fungi are
organic matter. Mushroom, yeast, mucor, etc. called saprophytes.
are examples of fungi.
GREEN Science (Biology) Book-9 297
Fig.
17.22 Yeast Mucor
Mushroom
Characteristics of fungi
1. Fungi do not contain root, stem and leaves.
2. They contain eukaryotic cells which may contain many nuclei.
3. Their cell wall is made of fungus cellulose.
4. Chlorophyll is absent in them.
5. Their body is made of hyphae, i.e. mycelia or long filaments.
6. They may be unicellular or multicellular.
7. They reproduce asexually by budding, fragmentation and sporulation.
Advantages of fungi
1. Fungi act on dead and decaying bodies and help in recycling of materials.
2. Edible fungi like mushroom provide us nutritious food.
3. Some fungi like yeast are used in bakeries and wine industries.
4. Some fungi are used for making medicine, e.g. penicillin.
Disadvantages of fungi
1. Fungi cause various diseases in plants and animals.
2. They attack leather, foods and spoil them.
3. They cause skin infection, vaginal yeast infection, etc. in humans.
Control Measures of Bacterial Diseases
1. Antibitotics should be used in case of bacterial infection.
2. The use of infected seeds should be avoided.
3. The infected animal should be stored properly in cold.
4. Salts should be used to control the growth of fungi in fruits and vegetables.
5. Sugar can be used to control fungi.
298 GREEN Science (Biology) Book-9
Control Measures of Viruses
1. The infected organisms should be isolated.
2. The infected parts of plants with viruses should be burnt.
3. We should avoid the use of personal materials of the patient.
4. By proper immunization against viral infections should be done.
5. Insects should be killed to avoid transmission of viruses.
Differences between Bacteria and Fungi
Bacteria Fungi
1. They are unicellular. 1. The may be unicellular or multicellular.
2. They have prokaryotic cell. 2. They have eukaryotic cell.
3. Nuclear membrane is absent. 3. Nuclear membrane is present.
Protozoa
Protozoa are the most primitive animals. They are unicellular and microscopic. So we can
see the detailed stricture of protozoa only under the compound microscope. Amoeba,
paramecium, euglena, plasmodium, trichomonas, etc. are some examples of protozoa.
Fig.
17.23 Paramecium Euglena Trichomonas
Amoeba
Some protozoa like amoeba, paramecium, euglena, etc. are harmless for human beings.
They do not cause any diseases.
Some protozoa like Plasmodium, Entamoeba, Giardia, Leishmania, Toxoplasma, etc.
cause various diseases in animals. So they are called harmful protozoa. The human
diseases causes by different types of protozoa are given below:
1. Malaria
2. Amoebiasis
3. Giardiasis
4. Babesiosis
5. Toxoplasmosis
6. Leishmaniasis
7. African sleeping sickness
Some protozoa live in the walls of intestine and others live in blood or body tissues. For
example, Entamoeba histolytica lives in the wall of intestine and plasmodium lives in blood.
GREEN Science (Biology) Book-9 299
Protozoa transmit from infected person to another by either of the following methods:
i. Through contaminated food and water
ii. By means of vectors like houseflies
iii. Through insect bite
iv. Direct contact with the patient
Control measures of protozoa
1. Consumption of contaminated food and water should be avoided.
2. We should avoid insect bite.
3. We should drink boiled water.
4. Personal hygiene should be maintained.
Key Concepts
1. All kinds of plants and animals have special characteristics in their bodies due to
which they can adapt in their habitat. These characteristics are called adaptational
characteristics. Similarly, the ability of an organism to adjust itself in its habitat is
called adaptation.
2. The animals that live in water are called aquatic animals. Examples, fish, dolphin,
octopus, etc. The plants that live in water are called aquatic plants. They are also
called hydrophytes.
3. The hydrophytes that float freely in water are called floating hydrophytes. Their
roots are not attached to the soil.
4. The hydrophytes that remain immersed in water are called submerged hydrohytes.
Their roots are attached to the soil.
5. Some hydropytes have roots fixed to the soil but their stem and leaves emerge out
of water. Such type of hydrophytes are called fixed and emergent hydrophytes.
6. Aquatic plants (hydrophytes) have very less developed root system. Some
hydrophytes do not have roots.
7. The body of hydrophytes remains covered with waxy substance. It prevents them
form decaying in water.
8. Aquatic animals have boat-shaped or streamlined body which helps them to swim
in water.
9. Aquatic animals have pointed head, smooth body and powerful tail. These features
help them to swim easily in water.
10. Aquatic animals have fins and tail to help them to swim in water they also help
them to change to direction in water.
11. The body of aquatic animals remains covered with water. proof scales or mucous
coat which prevents the body from decaying.
12. The organisms that live on land are called terrestrial organisms. They obtain food,
respiratory gas (oxygen) and shelter from land.
13. Xerophytes like cactus, aloe vera, oputia, etc have long and well developed root
system adapted to absorb maximum water from the soil.
300 GREEN Science (Biology) Book-9
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