Extra Important Long Answer Questions Chapter:7 Diversity in Living Organisms Class 9 Science
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1. What is the five-kingdom classification? Explain its characteristics.
Answer: The five-kingdom classification was proposed by R.H. Whittaker in 1969 and is based on cell structure, body organization, mode of nutrition, reproduction, and evolutionary relationships.
Five Kingdoms and Their Characteristics:
1. Monera:
Unicellular, prokaryotic organisms (no true nucleus).
Some have a cell wall (e.g., bacteria).
Reproduce asexually (binary fission).
Example: Bacteria, Cyanobacteria.
2. Protista:
Unicellular, eukaryotic organisms (have a nucleus).
Move using cilia, flagella, or pseudopodia.
Examples: Amoeba, Paramecium, Euglena.
3. Fungi:
Multicellular or unicellular, eukaryotic.
Heterotrophic (decomposers).
Have cell walls made of chitin.
Example: Yeast, Mushroom.
4. Plantae:
Multicellular, autotrophic (photosynthesis).
Cell wall made of cellulose.
Example: Mango tree, Rose plant.
5. Animalia:
Multicellular, heterotrophic (consume food).
No cell wall, show locomotion.
Example: Humans, Fish, Birds.
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2. Explain the classification of the plant kingdom.
Answer: The plant kingdom is classified into two major groups: Cryptogams (non-seed plants) and Phanerogams (seed plants).
1. Cryptogams (Non-seed Plants)
Thallophyta (Algae):
Simple, aquatic, photosynthetic plants.
No true roots, stems, or leaves.
Example: Spirogyra, Chlamydomonas.
Bryophyta (Mosses, Liverworts):
Live in moist environments.
No vascular tissues, reproduce through spores.
Example: Moss (Funaria), Liverwort (Marchantia).
Pteridophyta (Ferns):
Have vascular tissues (xylem & phloem).
Reproduce by spores, no seeds.
Example: Ferns, Horse-tail.
2. Phanerogams (Seed Plants)
Gymnosperms (Naked seed plants):
Seeds not enclosed in fruits.
Mostly woody trees.
Example: Pine, Cycas.
Angiosperms (Flowering plants):
Seeds enclosed in fruits.
Divided into Monocots (one seed leaf) and Dicots (two seed leaves).
Example: Mango, Sunflower.
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3. How are animals classified into different phyla? Explain with examples.
Answer: The animal kingdom is classified based on body structure, symmetry, and presence of a backbone.
1. Invertebrates (No backbone)
Porifera (Sponges):
Pore-bearing, simplest animals.
Example: Sycon, Sponge.
Coelenterata (Cnidaria):
Radial symmetry, tentacles with stinging cells.
Example: Hydra, Jellyfish.
Platyhelminthes (Flatworms):
Flat, bilaterally symmetrical, mostly parasitic.
Example: Tapeworm, Liver fluke.
Nematoda (Roundworms):
Cylindrical body, parasitic.
Example: Ascaris (intestinal worm).
Annelida (Segmented worms):
Body divided into segments, closed circulatory system.
Example: Earthworm, Leech.
Arthropoda (Jointed legs):
Largest phylum, exoskeleton present.
Example: Insects, Prawns, Spiders.
Mollusca (Soft-bodied animals):
Soft body, muscular foot for movement.
Example: Snail, Octopus.
Echinodermata (Spiny-skinned animals):
Radial symmetry, marine habitat.
Example: Starfish, Sea urchin.
2. Vertebrates (Have a backbone - Phylum Chordata)
Pisces (Fishes): Rohu, Shark.
Amphibia: Frog, Salamander.
Reptilia: Lizard, Snake.
Aves (Birds): Crow, Sparrow.
Mammalia: Humans, Dogs.
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4. What are the differences between Amphibians, Reptiles, and Mammals?
Answer:
Difference Between Amphibians, Reptiles, and Mammals
1. Amphibians:
1. Live in both water and on land.
2. Have moist, smooth skin (no scales).
3. Breathe through gills (in larvae) and lungs (in adults).
4. Have a 3-chambered heart.
5. Cold-blooded (body temperature changes with the environment).
6. Reproduce by external fertilization, laying soft eggs in water.
7. Examples: Frog, Salamander, Toad.
2. Reptiles:
1. Mostly live on land, some are aquatic.
2. Have dry, scaly skin to prevent water loss.
3. Breathe through lungs.
4. Have a 3-chambered heart (except crocodiles, which have a 4-chambered heart).
5. Cold-blooded like amphibians.
6. Reproduce by internal fertilization, lay leathery eggs on land.
7. Examples: Snake, Crocodile, Lizard, Turtle.
3. Mammals:
1. Mostly live on land, some live in water (e.g., Whales).
2. Have hair or fur on the body.
3. Breathe through lungs.
4. Have a 4-chambered heart.
5. Warm-blooded (can regulate body temperature).
6. Reproduce by internal fertilization, give birth to young ones (except monotremes like Platypus, which lay eggs).
7. Examples: Human, Dog, Whale, Elephant.
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5. What is Binomial Nomenclature? Explain with examples.
Answer:
Binomial nomenclature is the system of naming organisms using two Latin words: Genus and Species.
Proposed by Carl Linnaeus in the 18th century.
Example:
Homo sapiens (Human)
Mangifera indica (Mango)
Rules of Binomial Nomenclature:
1. The first word (Genus) starts with a capital letter.
2. The second word (Species) starts with a small letter.
3. The name is written in italics or underlined when handwritten.
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6. What are the major characteristics of Mammals?
Answer:
1. Warm-blooded animals (maintain constant body temperature).
2. Have mammary glands to produce milk for young ones.
3. Body covered with hair or fur for insulation.
4. Give birth to young ones (except monotremes like Platypus).
5. Have a four-chambered heart for efficient circulation.
6. Examples: Humans, Elephants, Whales.
7. What are the major characteristics of Phylum Arthropoda?
Answer:
1. Largest phylum of the animal kingdom.
2. Exoskeleton made of chitin for protection.
3. Segmented body divided into head, thorax, and abdomen.
4. Jointed appendages (legs, antennae, claws, etc.).
5. Open circulatory system with hemolymph instead of blood.
6. Examples: Insects (Butterfly), Arachnids (Spider), Crustaceans (Crab).
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8. What are the different types of symmetry in animals? Explain with examples.
Answer:
1. Asymmetry: No definite shape or symmetry.
Example: Sponges (Porifera).
2. Radial Symmetry: Body can be divided into equal halves along multiple planes.
Example: Starfish (Echinodermata), Jellyfish (Cnidaria).
3. Bilateral Symmetry: Body can be divided into two equal halves along one plane.
Example: Humans, Earthworms, Insects.
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9. How are vertebrates classified into different groups?
Answer: Vertebrates belong to Phylum Chordata and are divided into five classes:
1. Pisces (Fishes):
Live in water, breathe through gills, have fins.
Examples: Shark, Rohu.
2. Amphibia:
Live on land and water, breathe through gills (larvae) and lungs (adults).
Examples: Frog, Salamander.
3. Reptilia:
Dry, scaly skin, cold-blooded, lay eggs on land.
Examples: Lizard, Crocodile.
4. Aves (Birds):
Feathers, beak, warm-blooded, lay eggs.
Examples: Sparrow, Peacock.
5. Mammalia:
Warm-blooded, give birth, have mammary glands.
Examples: Human, Elephant.
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10. What are the characteristics of Phylum Echinodermata?
Answer:
1. Marine animals with spiny skin.
2. Radial symmetry in adults, bilateral symmetry in larvae.
3. Move using tube feet (water vascular system).
4. Can regenerate lost body parts.
5. Have an endoskeleton made of calcium carbonate.
6. Examples: Starfish, Sea Urchin.
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11. What are the adaptations of terrestrial plants?
Answer:
1. Roots grow deep to absorb water.
2. Leaves have cuticles to reduce water loss.
3. Stomata regulate gas exchange and transpiration.
4. Xylem transports water efficiently.
5. Some plants store water (e.g., Cactus stores water in stems).
6. Examples: Neem, Cactus, Banyan Tree.
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12. What is the importance of classification?
Answer:
1. Helps in organizing diverse organisms into groups.
2. Makes it easy to study similarities and differences.
3. Helps in identifying new species.
4. Provides a scientific name for every organism (Binomial Nomenclature).
5. Shows evolutionary relationships among organisms.
6. Helps in biological research and conservation.
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13. Differentiate between Bryophytes and Pteridophytes.
Answer:
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14. What are the characteristics of Phylum Annelida?
Answer:
1. Segmented body (metameric segmentation).
2. Closed circulatory system with blood vessels.
3. Bilateral symmetry with a true coelom.
4. Locomotion using setae or parapodia.
5. Examples: Earthworm, Leech.
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15. Explain the classification of Angiosperms.
Answer: Angiosperms (flowering plants) are classified into two groups:
1. Monocots (Monocotyledons):
Single seed leaf (cotyledon).
Parallel leaf venation.
Fibrous root system.
Example: Rice, Maize, Grass.
2. Dicots (Dicotyledons):
Two seed leaves (cotyledons).
Reticulate leaf venation.
Tap root system.
Example: Mango, Rose, Sunflower.
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16. What are the main characteristics of Phylum Mollusca?
Answer:
1. Soft-bodied animals with a calcium carbonate shell (in some).
2. Unsegmented body divided into head, foot, and visceral mass.
3. Have a muscular foot for movement.
4. Open circulatory system (except cephalopods like octopuses).
5. Examples: Snail, Octopus, Clam.
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17. What are the different types of plant tissues?
Answer:
1. Meristematic Tissue: Responsible for growth (e.g., root tips).
2. Parenchyma: Stores food, performs photosynthesis.
3. Collenchyma: Provides flexibility and support.
4. Sclerenchyma: Provides strength and rigidity.
5. Xylem: Transports water and minerals.
6. Phloem: Transports food.
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18. Why are amphibians called "cold-blooded" animals?
Answer:
1. Their body temperature changes with the environment.
2. They are active in warm temperatures and inactive in cold.
3. They hibernate during winter (e.g., frogs).
4. They bask in the sun to warm up.
5. Examples: Frog, Toad, Salamander.
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19. What are the major characteristics of reptiles?
Answer:
1. Cold-blooded vertebrates.
2. Dry, scaly skin to prevent water loss.
3. Breathe through lungs.
4. Internal fertilization, lay amniotic eggs on land.
5. Examples: Lizard, Snake, Crocodile.
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20. Explain the structure and function of the water vascular system in Echinoderms.
Answer:
1. Network of fluid-filled canals used for movement, respiration, and feeding.
2. Tube feet (podia) help in locomotion.
3. Madreporite is the entry point for water.
4. Ring canal and radial canals distribute water.
5. Used for capturing prey and exchanging gases.
6. Example: Starfish.
