Diversity in Living World – MCQs with Answers and Explanations
How to use: Read the question and choose the best option. Click Show Answer & Explanation to reveal the correct option and a clear concept explanation. These are grouped topic-wise for focused practice.
Basics of Diversity (1–6)
1. What does 'diversity' mean in the biological context?
Correct: B. Diversity (biodiversity) refers to the variety of life forms — plants, animals, fungi and microorganisms — in a given area. It is not limited to only plants or animals.
2. Which of the following is an example of biodiversity at the species level?
Correct: A. The presence of different bird species shows species-level biodiversity. Rocks and temperature are non-living; population counts are not species diversity metrics.
3. Why is biodiversity important for humans?
Correct: B. Biodiversity supplies food, medicines, raw materials and keeps ecosystems functioning (pollination, nutrient cycling), which are essential for human survival.
4. Which group includes organisms that make their own food?
Correct: C. Producers (like green plants) make their own food by photosynthesis. Consumers eat other organisms; decomposers break down dead matter.
5. Which term correctly describes organisms like bacteria and fungi that break down dead matter?
Correct: C. Decomposers (fungi and many bacteria) decompose dead organisms and recycle nutrients back to the soil.
6. A single-celled organism is called ________.
Correct: B. Unicellular organisms (like many bacteria and protozoa) consist of a single cell performing all life functions.
Characteristics of Living Organisms (7–13)
7. Which of the following is NOT a characteristic of living organisms?
Correct: C. Photosynthesis is a process some organisms (plants) perform, but it is not a universal characteristic of all living organisms. Growth, reproduction and excretion are common to all living beings.
8. Which process releases energy from food in living organisms?
Correct: C. Respiration breaks down food to release energy used for growth, movement and other life processes. Photosynthesis produces food in plants.
9. Which of these is an example of movement in plants?
Correct: B. Leaves bending toward light (phototropism) is a plant movement response to stimuli. The other options are animal movements (locomotion).
10. What is excretion?
Correct: B. Excretion is removing metabolic wastes (like urine, CO₂) from the body to maintain internal balance.
11. Which of the following is necessary for reproduction in living organisms?
Correct: C. Reproduction is the biological process by which organisms produce new individuals of the same kind.
12. Sensitivity in organisms refers to their ability to:
Correct: B. Sensitivity (responsiveness) is the ability to notice and react to stimuli like light, heat or touch.
13. Which one shows unicellular life?
Correct: A. Yeast is unicellular (single-celled fungus). The others are multicellular organisms.
Plants — Structure, Types & Functions (14–22)
14. Which pigment helps plants capture sunlight for photosynthesis?
Correct: B. Chlorophyll is the green pigment in leaves that traps sunlight for photosynthesis.
15. Which plant type has a woody stem and lives many years?
Correct: C. Trees have a single main woody stem (trunk) and often live many years; herbs have soft stems.
16. Where are seeds usually formed in flowering plants?
Correct: B. After fertilisation, the ovule develops into a seed and the ovary becomes the fruit that contains the seed(s).
17. Which of these is NOT a plant habit category?
Correct: C. Mammal is an animal class, not a plant habit. Shrub, herb and climber are plant habit types.
18. What is the main function of roots?
Correct: C. Roots anchor the plant and absorb water and minerals from the soil for transport to other parts of the plant.
19. Stomata are mainly involved in:
Correct: B. Stomata are openings on leaves that allow exchange of gases (CO₂ in, O₂ out) and water vapour loss (transpiration).
20. Photosynthesis requires all EXCEPT:
Correct: D. Photosynthesis uses sunlight, CO₂ and water with chlorophyll to make food. Animal food is not required by plants for photosynthesis.
Animals — Types & Adaptations (21–28)
21. An animal with a backbone is called a:
Correct: B. Vertebrates have a backbone (e.g., mammals, birds, fishes). Invertebrates lack a backbone.
22. Which animal is an example of an insect?
Correct: B. Butterflies are insects (six legs, three body parts). Spiders are arachnids (eight legs).
23. Which animal group has feathers?
Correct: C. Birds have feathers and wings adapted for flight or insulation; feathers are unique to birds.
24. Fins and streamlined bodies are adaptations for:
Correct: B. Fins and streamlined shapes reduce resistance in water, aiding swimming (common in fishes and aquatic animals).
25. An animal that eats only plants is called a:
Correct: B. Herbivores (e.g., cow) eat plants. Carnivores eat other animals; omnivores eat both.
26. Which adaptation helps animals avoid predators at night?
Correct: B. Nocturnal behaviour (being active at night) helps animals avoid daytime predators and exploit night-time food sources (e.g., bats).
27. Which of the following is TRUE about mammals?
Correct: C. Most mammals produce milk to feed their young. Feathers are for birds; photosynthesis is for plants.
28. Which structure helps birds to fly?
Correct: B. Feathers and wings provide lift and enable flight; gills are for aquatic respiration and scales for some animals.
Fungi & Microorganisms (29–33)
29. Which of the following is a fungus?
Correct: B. Yeast is a unicellular fungus used in fermentation. Algae are photosynthetic; amoeba is a protozoan; fern is a plant.
30. Which microorganism helps in making curd?
Correct: B. Lactic acid bacteria (e.g., Lactobacillus) ferment milk to make curd, a beneficial use of microbes.
31. Fungi are different from plants because they:
Correct: B. Fungi lack chlorophyll and absorb nutrients from dead/decaying matter; they are mainly decomposers. Some fungi are unicellular, some multicellular, but they do not produce seeds.
32. Which of these is a harmful effect of some microorganisms?
Correct: A. Some microbes are pathogenic and cause diseases in humans, animals and plants; others have beneficial roles like digestion and fermentation.
33. Which process uses yeast to produce carbon dioxide that makes dough rise?
Correct: B. Fermentation by yeast converts sugars into CO₂ and alcohol; CO₂ causes the dough to rise in bread making.
Classification & Habitat (34–38)
34. Classification helps us to:
Correct: B. Classification groups organisms by shared features, helping in identification, study and communication about living organisms.
35. Which of the following is NOT a basis for simple classification at class 6 level?
Correct: D. Colour of clothing is irrelevant; classification uses observable biological features like structure, nutrition and habitat.
36. A cactus with thick stems and spines is adapted to live in:
Correct: C. Desert plants like cactus store water in thick stems and have spines to reduce water loss and deter herbivores — adaptations for arid habitats.
37. Which habitat would you expect earthworms to be most abundant in?
Correct: B. Earthworms thrive in moist, nutrient-rich soil where they can feed on organic matter and help aerate and enrich the soil.
Biodiversity, Food Chains & Conservation (38–40)
38. In the food chain Grass → Rabbit → Fox, which is the primary consumer?
Correct: B. Rabbit eats grass (producer), so rabbit is the primary consumer. Fox is a secondary consumer (predator).
39. Which one is a simple way students can help conserve local biodiversity?
Correct: B. Planting native trees and preventing pollution are simple, effective steps to conserve local biodiversity and habitats.
40. Why are pollinators like bees important for biodiversity?
Correct: B. Bees and other pollinators transfer pollen between flowers enabling fertilisation, fruit and seed production — critical for plant reproduction and food supply.