NSO Olympiad Class 6 Science – Diversity in the Living World
NSO Olympiad-level Class 6 Science questions from “Diversity in the Living World.” Includes MCQs, HOTS, answer key and detailed explanations on biodiversity, plant classification, roots, venation, habitats and adaptations.
Section A — Olympiad-Level Questions
1. A student observes Plant P: short, green tender stem, parallel leaf venation. Which combination is MOST likely for P?
A. Taproot and two cotyledons
B. Fibrous roots and one cotyledon
C. Taproot and one cotyledon
D. Fibrous roots and two cotyledons
2. Plant X has a hard, brown stem. Its branches begin very close to the ground and the stem is thinner than that of a mango plant. Plant X should be classified as a:
A. Herb
B. Shrub
C. Tree
D. Creeper
3. Which observation would provide the STRONGEST evidence that an unknown plant is a dicot?
A. It is taller than a student
B. It has bright flowers
C. It has reticulate venation and a taproot
D. It grows in a forest
4. Riya groups a rose and a mango together because both have hard brown stems. Aman separates them. Which extra feature best justifies Aman’s grouping?
A. Presence of leaves
B. Place where branches arise
C. Need for sunlight
D. Presence of roots
5. A leaf shows veins running side by side. Without uprooting the plant, which prediction is most reasonable?
A. It probably has fibrous roots
B. It definitely has no roots
C. It probably has a taproot
D. It must be a shrub
6. Four plants are recorded: P—reticulate/taproot; Q—parallel/fibrous; R—reticulate/fibrous; S—parallel/fibrous. Which record should be rechecked first?
A. P
B. Q
C. R
D. S
7. Which pair is correctly matched with the chapter’s examples?
A. Chickpea—monocot—fibrous root
B. Wheat—dicot—taproot
C. Chickpea—dicot—reticulate venation
D. Maize—dicot—parallel venation
8. A plant has a weak stem and grows upward only by taking support from another object. It is best described as a:
A. Creeper
B. Climber
C. Shrub
D. Tree
9. Which grouping criterion can be meaningfully applied to BOTH plants and animals as discussed in the chapter?
A. Cotyledon number
B. Leaf venation
C. Habitat/place where they live
D. Root system
10. A pigeon and a housefly are placed in one group based only on movement. What feature supports this grouping?
A. Both use fins
B. Both walk and fly using legs and wings
C. Both crawl using legs only
D. Both live only on trees
11. Which conclusion is BEST supported by comparing a fish and a goat?
A. All animals use the same organs for movement
B. Movement structures can be related to the surroundings in which an animal lives
C. Only aquatic animals show adaptations
D. Body shape does not affect movement
12. A cactus with thick fleshy stems is moved from a desert to a region with abundant water. The thick fleshy stem was originally useful mainly because it:
A. allowed snow to slide off
B. stored water
C. helped the plant fly
D. produced fibrous roots
13. Why are the conical shape and sloping branches of deodar trees useful in cold mountains?
A. They trap desert sand
B. They allow snow to slide off easily
C. They store food for winter
D. They help the roots float
14. Hot-desert camels have long legs and wide hooves. Which problem do these features most directly help solve?
A. Swimming in deep water
B. Moving over sandy ground without sinking easily
C. Climbing trees
D. Flying over dunes
15. Compared with a hot-desert camel, a cold-desert camel of Ladakh is described as having:
A. shorter legs and two humps
B. longer legs and no hump
C. fins and one hump
D. webbed feet and two humps
16. Which set of features would help a camel conserve water most effectively?
A. Heavy sweating, wet dung, much urine
B. No sweating, dry dung, small amount of urine
C. Large leaves, soft stem, much urine
D. Webbed feet, fins, heavy sweating
17. Rhododendrons in windy mountain-top Shola forests may be shorter and have smaller leaves than rhododendrons elsewhere. This is an example of:
A. grouping
B. adaptation
C. migration
D. germination
18. Which statement correctly distinguishes habitat from adaptation?
A. Habitat is a body part; adaptation is a place
B. Habitat is where an organism lives; adaptation is a feature helping it survive there
C. Both mean exactly the same thing
D. Habitat applies only to plants
19. Which of the following is an aquatic habitat?
A. Grassland
B. Mountain
C. River
D. Desert
20. A frog is difficult to place exclusively in either an aquatic or terrestrial group because it:
A. has no habitat
B. lives in both water and on land
C. has wings
D. is a plant
21. A wetland is damaged and a local bird loses nesting places and food. Which sequence is most consistent with the chapter?
A. Habitat damage → more resources → increased biodiversity
B. Habitat damage → loss of homes/food → possible loss of biodiversity
C. Habitat damage → new cotyledons → more plants
D. Habitat damage → parallel venation → more animals
22. Why is grouping organisms scientifically useful?
A. It proves all organisms are identical
B. It makes it easier to understand and study similarities and differences
C. It eliminates biodiversity
D. It changes an organism’s habitat
23. A class groups animals first by food, another group by movement, and a third by habitat. Which statement is correct?
A. Only the first group can be correct
B. Different valid criteria can produce different groupings
C. Animals cannot be grouped
D. A grouping is valid only if based on colour
24. Trees provide food and shelter to birds, while some animals spread seeds after eating fruits. This most strongly shows that:
A. living organisms in a region can depend on one another
B. animals never depend on plants
C. only trees contribute to biodiversity
D. seed dispersal destroys habitats
25. A mystery seed has two cotyledons. Which complete prediction is MOST consistent with the chapter?
A. Parallel venation + fibrous root
B. Reticulate venation + taproot
C. Parallel venation + taproot
D. No venation + no roots
Answer Key – Detailed Explanations
1. Answer: B — Parallel venation is generally associated with fibrous roots and monocot seeds having one cotyledon.
2. Answer: B — Shrubs have hard, woody stems with branches arising close to the ground; their stems are generally thinner than tree trunks.
3. Answer: C — The links dicots with two cotyledons, reticulate venation and a taproot system.
4. Answer: B — A mango tree typically branches higher up the stem, while a rose shrub branches close to the ground.
5. Answer: A — Plants with parallel venation generally have fibrous roots.
6. Answer: C — The general relation in the chapter is reticulate venation ↔ taproot and parallel venation ↔ fibrous roots, so R is inconsistent.
7. Answer: C — Chickpea is a dicot with reticulate venation and a taproot. Wheat and maize are monocot examples.
8. Answer: B — Climbers have weak stems and need support to climb and grow; creepers spread along the ground.
9. Answer: C — Both plants and animals can be grouped by surroundings or habitat; the other criteria are plant-specific.
10. Answer: B — The movement table lists both pigeon and housefly as walking and flying, using legs and wings.
11. Answer: B — Fish use fins and streamlined bodies in water, while goats use legs on land, showing a relation between surroundings and movement.
12. Answer: B — Desert plants such as cactus have thick, fleshy stems that store water and help them tolerate dry, hot conditions.
13. Answer: B — These features prevent heavy snow from accumulating on the branches.
14. Answer: B —long legs and wide hooves help hot-desert camels walk on sand without sinking.
15. Answer: A — Cold-desert camels have comparatively shorter legs suited to mountainous terrain and two humps.
16. Answer: B — These features reduce water loss and help camels survive for many days without drinking.
17. Answer: B — Adaptations are special features that enable organisms to survive in the conditions of a particular region.
18. Answer: B —habitat as the place where an organism lives and adaptations as special survival-enabling features.
19. Answer: C — Ponds, lakes, rivers and oceans are examples of aquatic habitats.
20. Answer: B — Frogs can live in water as well as on land and are described as amphibians.
21. Answer: B — Damage to habitats can remove homes, food and other resources, contributing to biodiversity loss.
22. Answer: B —grouping makes plants and animals easier to understand and study based on similarities and differences.
23. Answer: B —different students may choose different common features, so multiple useful groupings are possible.
24. Answer: A — These examples demonstrate interdependence among plants and animals within biodiversity.
25. Answer: B — Two cotyledons indicate a dicot; dicots generally have reticulate venation and a taproot system.
biodiversity; grouping; herbs, shrubs, trees, climbers and creepers; venation; roots; monocots/dicots; animal movement; habitats; adaptations; interdependence; and biodiversity conservation.