Green Science 9 Final PDF (2076)

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