Extra 30 short answer questions from the chapter:7 "Diversity in Living Organisms" for Class 9 CBSE Science:-
1. Why do we classify organisms?
Answer:
To make the study of organisms easier.
To understand evolutionary relationships.
To identify similarities and differences among species.
To systematically arrange organisms into groups.
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2. What is the basis of the five-kingdom classification?
Answer: The five-kingdom classification is based on:
Cell structure (Prokaryotic or Eukaryotic)
Body organization (Unicellular or Multicellular)
Mode of nutrition (Autotrophic or Heterotrophic)
Reproduction (Asexual or Sexual)
Phylogenetic relationships (Evolutionary history)
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3. What are the five kingdoms in Whittaker’s classification?
Answer: The five kingdoms are:
1. Monera (Bacteria, Cyanobacteria)
2. Protista (Amoeba, Paramecium)
3. Fungi (Mushrooms, Yeast)
4. Plantae (Mango tree, Rose plant)
5. Animalia (Humans, Fish)
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4. Differentiate between Monera and Protista.
Answer:
Difference Between Monera and Protista
Monera are prokaryotes (no true nucleus), while Protista are eukaryotes (have a nucleus).
Monera have simple cell structures, while Protists are more advanced and complex.
Monera reproduce only asexually, while Protists reproduce both sexually and asexually.
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5. How are fungi different from plants?
Answer:
Fungi are heterotrophic, whereas plants are autotrophic.
Fungi have chitin in their cell wall, while plants have cellulose.
Fungi reproduce by spores, while plants reproduce by seeds/spores.
Fungi lack chlorophyll, whereas plants have chlorophyll for photosynthesis.
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6. What are the major characteristics of kingdom Plantae?
Answer:
Eukaryotic and multicellular.
Autotrophic (photosynthesis).
Cell wall made of cellulose.
Store food as starch.
Reproduce sexually or asexually.
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7. How do vertebrates differ from invertebrates?
Answer:
Difference Between Vertebrates and Invertebrates
Vertebrates have a backbone, while invertebrates do not.
Vertebrates have a complex nervous system, while invertebrates have a simpler one.
Vertebrates generally have a closed circulatory system, whereas invertebrates can have open or closed systems.
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8. Explain the characteristic features of Phylum Porifera.
Answer:
Simplest multicellular organisms.
Body has pores (Ostia and Osculum).
No tissues, organs, or organ systems.
Marine habitat (mostly).
Example: Sponges.
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9. What are the characteristics of Phylum Coelenterata?
Answer:
Radial symmetry.
Body cavity (coelenteron) present.
Tentacles with stinging cells.
Examples: Hydra, Jellyfish.
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10. What are the features of Annelida?
Answer:
Bilateral symmetry.
Segmented body.
Closed circulatory system.
Examples: Earthworm, Leech.
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11. Explain the features of Phylum Arthropoda.
Answer:
Largest phylum in the animal kingdom.
Jointed legs and segmented body.
Exoskeleton made of chitin.
Examples: Insects, Prawns, Spiders.
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12. How do fish differ from amphibians?
Answer:
Difference Between Fish and Amphibians
Fish are fully aquatic, while amphibians can live both in water and on land.
Fish breathe through gills, whereas amphibians use gills (as larvae) and lungs/skin (as adults).
Fish have scales, while amphibians have moist, smooth skin.
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13. What are the adaptations of birds for flight?
Answer:
Hollow bones (lightweight skeleton).
Feathers for insulation and aerodynamics.
Wings for flight.
Strong flight muscles.
Four-chambered heart for efficient oxygen supply.
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14. Explain the classification of plants based on seed production.
Answer:
Cryptogams (Non-seed plants) – Algae, Mosses, Ferns.
Phanerogams (Seed plants) – Gymnosperms (Pine, Cycas) and Angiosperms (Mango, Rose).
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15. Differentiate between Gymnosperms and Angiosperms.
Answer:
Difference Between Gymnosperms and Angiosperms
Gymnosperms have naked seeds, while Angiosperms have seeds enclosed in fruits.
Gymnosperms do not have flowers, whereas Angiosperms produce flowers.
Gymnosperms mainly rely on wind for pollination, while Angiosperms have diverse pollination methods.
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16. What are the characteristics of Amphibians?
Answer:
Live in water and land.
Moist skin without scales.
Cold-blooded (ectothermic).
Lay eggs in water.
Examples: Frog, Salamander.
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17. What are the characteristics of Mammals?
Answer:
Warm-blooded vertebrates.
Mammary glands for milk production.
Body covered with hair/fur.
Give birth to young ones (except monotremes).
Examples: Humans, Tigers, Whales.
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18. What is Binomial Nomenclature?
Answer:
A scientific naming system using two names.
Given by Linnaeus.
Example: Homo sapiens (Humans).
First name = Genus, Second name = Species.
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19. Why are Bryophytes called Amphibians of the Plant Kingdom?
Answer:
Live on land but need water for reproduction.
Lack vascular tissues.
Example: Mosses, Liverworts.
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20. What are the major phyla of the Animal Kingdom?
Answer:
1. Porifera – Sponges
2. Coelenterata – Jellyfish
3. Platyhelminthes – Flatworms
4. Annelida – Earthworm
5. Arthropoda – Insects
6. Mollusca – Snails
7. Echinodermata – Starfish
8. Chordata – Vertebrates
21. Define bilateral and radial symmetry.
Answer:
Bilateral Symmetry: The body can be divided into two equal halves along one plane. Example: Humans, Earthworm.
Radial Symmetry: The body can be divided into equal halves along multiple planes passing through a central axis. Example: Starfish, Jellyfish.
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22. Differentiate between unicellular and multicellular organisms.
Answer:
Difference Between Unicellular and Multicellular Organisms
Unicellular Organisms:
1. Made up of a single cell.
2. One cell performs all life functions (nutrition, respiration, reproduction, etc.).
3. Generally microscopic in size.
4. Reproduce mostly through asexual methods like binary fission or budding.
5. Have a shorter lifespan.
6. Examples: Amoeba, Bacteria, Paramecium.
Multicellular Organisms:
1. Made up of many cells.
2. Different cells perform specialized functions (e.g., nerve cells, muscle cells).
3. Can be small or large in size.
4. Reproduce through both asexual and sexual reproduction.
5. Have a longer lifespan.
6. Examples: Humans, Trees, Dogs.
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23. What are the characteristics of phylum Mollusca?
Answer:
Soft-bodied animals, usually with a shell.
Unsegmented body divided into head, foot, and visceral mass.
Open circulatory system (except cephalopods).
Examples: Snail, Octopus, Pila.
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24. How do reptiles adapt to a terrestrial environment?
Answer:
Dry, scaly skin prevents water loss.
Lungs for respiration instead of gills.
Internal fertilization to protect embryos.
Amniotic eggs with a tough shell prevent drying out.
Examples: Lizard, Crocodile, Snake.
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25. Explain the water vascular system in Echinoderms.
Answer:
A network of fluid-filled canals used for movement, food transport, and respiration.
Tube feet (podia) help in locomotion and capturing food.
Found in Echinoderms like Starfish and Sea Urchins.
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26. Differentiate between vascular and nonvascular plants.
Answer:
Difference Between Vascular and Nonvascular Plants
Vascular Plants:
1. Have well-developed vascular tissues (xylem and phloem) for transport of water and nutrients.
2. Can grow tall and large due to efficient transport systems.
3. Have true roots, stems, and leaves.
4. Found in both terrestrial and aquatic environments.
5. Examples: Ferns, Pine trees, Mango trees, Roses.
Non-Vascular Plants:
1. Lack vascular tissues (xylem and phloem), so they absorb water directly from their surroundings.
2. Generally small and grow close to the ground.
3. Do not have true roots, stems, or leaves (have root-like, stem-like, and leaf-like structures).
4. Mostly found in moist and shady places.
5. Examples: Mosses, Liverworts, Hornworts.
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27. Give an example of a cartilaginous and a bony fish.
Answer:
Cartilaginous Fish: Shark (Chondrichthyes) – skeleton made of cartilage.
Bony Fish: Rohu (Osteichthyes) – skeleton made of bones.
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28. What are the main features of Phylum Platyhelminthes?
Answer:
Flat, ribbon-like body (hence, "flatworms").
Bilateral symmetry with a simple digestive system.
Mostly parasitic (e.g., Tapeworm, Liver fluke).
Lack a true body cavity (Acoelomate).
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29. What are the three domains of life?
Answer:
Bacteria: Unicellular prokaryotes (e.g., E. coli).
Archaea: Extremophiles, prokaryotic but different from bacteria (e.g., Thermophiles).
Eukarya: Eukaryotic organisms including Protists, Fungi, Plants, and Animals.
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30. Why are reptiles called cold-blooded animals?
Answer:
Reptiles cannot regulate their body temperature internally.
Their body temperature changes with the environment (ectothermic).
They bask in the sun to warm up and seek shade to cool down.
Examples: Snake, Lizard, Crocodile.
