NSO CLASS 5 SCIENCE OLYMPIAD Reproduction in Plants – 25 Olympiad-Level MCQs With Detailed Answers & Explanations

Section A: Questions

Q1. In the structure of a kidney bean seed, which part stores food for the developing baby plant?

(A) Seed coat

(B) Seed hole

(C) Cotyledon

(D) Embryo axis

Q2. A gram seed is classified as a dicot seed. What does this tell us about its cotyledons, and which of the following is also a dicot seed?

(A) One cotyledon; rice is also a dicot

(B) Two cotyledons; beans are also dicot seeds

(C) No cotyledon; wheat is also a dicot

(D) Three cotyledons; maize is also a dicot

Q3. Assertion (A): The seed coat completely protects the embryo by preventing any water or air from entering the seed.

Reason (R): The seed coat is a tough outer covering of the seed.

Choose the correct option.

(A) Both A and R are true, and R correctly explains A

(B) Both A and R are true, but R does not correctly explain A

(C) A is true, but R is false

(D) A is false, but R is true

Q4. Which structure in a seed specifically allows water to enter so that germination can begin?

(A) Cotyledon

(B) Embryo

(C) Seed hole

(D) Seed coat

Q5. In the ‘Let’s Experiment’ activity, gram seeds are soaked in water for two days. What is the best explanation for why the outer covering of the seed swells up?

(A) The seed coat converts into a cotyledon

(B) Water enters through the seed hole and is absorbed, causing the covering to swell

(C) The embryo starts photosynthesising immediately

(D) The seed changes into a spore

Q6. Lotus seeds are able to float and disperse on water mainly because of which feature?

(A) Hook-like spikes on the seed surface

(B) Wing-like structures for gliding

(C) Porous parts in the seed that trap air

(D) A very heavy, dense seed coat

Q7. A floating coconut can travel long distances across the sea before its seed germinates on a new shore. Which feature of the coconut seed makes this possible?

(A) A spongy, fibrous covering that helps it float

(B) Hooks that catch onto ocean currents

(C) Hair-like structures that act like sails

(D) An explosive fruit that bursts in water

Q8. Both dandelion and maple seeds are dispersed by wind, but they use different features to do so. Which statement correctly matches each plant with its wind-dispersal feature?

(A) Dandelion has wing-like structures; maple has fine hair

(B) Dandelion has fine hair around its seeds; maple seeds have wings

(C) Both dandelion and maple seeds have hooks

(D) Both dandelion and maple seeds are dispersed by explosion, not wind

Q9. Which of these seeds is best adapted to spin and glide away from the parent plant when caught by the wind?

(A) Cocklebur seed

(B) Maple seed

(C) Coconut seed

(D) Pea seed

Q10. Balsam and pea plants disperse their seeds mainly through which method?

(A) Dispersal by wind

(B) Dispersal by water

(C) Dispersal by explosion

(D) Dispersal by animals

Q11. The seeds of cocklebur are dispersed by animals. What feature of the cocklebur seed makes this possible?

(A) A spongy, air-filled covering

(B) Hooks or spikes that stick to fur or clothing

(C) Fine hair that catches the wind

(D) Wing-like extensions

Q12. Why is dispersal of seeds away from the parent plant important for the survival of a new plant?

(A) It makes the seeds heavier so they can grow faster

(B) It reduces competition with the parent plant for sunlight, water, nutrients and space

(C) It converts seeds into spores for better growth

(D) It stops the seeds from ever germinating

Q13. Which of the following correctly shows the order of the stages of germination in a seed?

(A) Shoot grows upward → seed absorbs water → roots develop → leaves appear

(B) Seed gets water, air and warmth → seed coat breaks and baby plant grows → roots and shoot develop → young plant grows and leaves develop

(C) Leaves develop first → then roots → then the seed coat breaks

(D) Roots and shoot appear before the seed absorbs any water

Q14. During germination, which part of the young seedling typically grows downward into the soil first?

(A) The shoot

(B) The leaves

(C) The root

(D) The cotyledon

Q15. Just after germination begins, before true leaves have formed, from where does the tiny seedling mainly get its food?

(A) From sunlight directly

(B) From the soil’s minerals alone

(C) From the cotyledons

(D) From nearby mature plants

Q16. The method of growing new plants from vegetative parts such as roots, stems and leaves (instead of seeds) is called:

(A) Germination

(B) Dispersal

(C) Vegetative propagation

(D) Agriculture

Q17. New plants can grow directly from the roots of which group of plants?

(A) Rose, Hibiscus and money plant

(B) Carrot, sweet potato, turnip, radish and dahlia

(C) Potato, ginger and onion

(D) Bryophyllum and Begonia

Q18. A potato can grow into a new plant from a small part of its surface called an ‘eye’. What exactly is this ‘eye’?

(A) A modified root

(B) A bud on the underground stem

(C) A cotyledon

(D) A spore-producing structure

Q19. Bryophyllum and Begonia are able to grow new plants from which vegetative part?

(A) Their roots

(B) Their underground stems

(C) Buds on the margins of their leaves

(D) Spores on their leaves

Q20. Rose, Hibiscus and money plant are commonly grown as new plants using which method?

(A) Stem cutting

(B) Root cutting

(C) Spore germination

(D) Seed dispersal by explosion

Q21. Ferns reproduce through spores. Where on the fern plant are these spores usually found?

(A) On the roots

(B) On the underside of the leaves

(C) Inside the stem only

(D) On the flower petals

Q22. Apart from ferns, which other living things mentioned in the chapter also reproduce through spores?

(A) Cactus and grasses

(B) Carrot and potato

(C) Fungi like mushroom and bread mould

(D) Rose and Hibiscus

Q23. The practice of growing plants on a large scale for food and other purposes is known as:

(A) Vegetative propagation

(B) Germination

(C) Agriculture

(D) Dispersal

Q24. In the standard steps of agriculture (ploughing, manuring, sowing, irrigation, spraying pesticides, harvesting), which step comes immediately after sowing?

(A) Ploughing

(B) Manuring

(C) Irrigation

(D) Harvesting

Q25. Rice, maize and cotton are examples of kharif crops. What does this indicate about how and when they are grown?

(A) They are grown from November to April and need very little water

(B) They are grown from June to October and depend on monsoon rains

(C) They can be grown in any season without water

(D) They grow only underground like potatoes

 

 

Section B: Answer Key (Quick Reference)

Q1: C	Q2: B	Q3: D	Q4: C	Q5: B
Q6: C	Q7: A	Q8: B	Q9: B	Q10: C
Q11: B	Q12: B	Q13: B	Q14: C	Q15: C
Q16: C	Q17: B	Q18: B	Q19: C	Q20: A
Q21: B	Q22: C	Q23: C	Q24: C	Q25: B

 

 

Section C: Answers with Detailed Explanations

Q1. In the structure of a kidney bean seed, which part stores food for the developing baby plant?

Correct Answer: (C) Cotyledon

Explanation: The cotyledon is the food-storing part of the seed. It nourishes the embryo until the plant develops leaves and can make its own food through photosynthesis.

Q2. A gram seed is classified as a dicot seed. What does this tell us about its cotyledons, and which of the following is also a dicot seed?

Correct Answer: (B) Two cotyledons; beans are also dicot seeds

Explanation: Seeds with two cotyledons, like gram and beans, are called dicot seeds. Seeds with only one cotyledon, such as rice and wheat, are called monocot seeds.

Q3. Assertion (A): The seed coat completely protects the embryo by preventing any water or air from entering the seed.

Reason (R): The seed coat is a tough outer covering of the seed.

Choose the correct option.

Correct Answer: (D) A is false, but R is true

Explanation: The seed coat is indeed a tough outer covering (R is true), but it does not block all water and air — a tiny opening called the seed hole lets water enter for germination. So statement A is false while R is true.

Q4. Which structure in a seed specifically allows water to enter so that germination can begin?

Correct Answer: (C) Seed hole

Explanation: The seed hole is a small opening in the seed coat that lets water enter the seed, which is a necessary first step for germination.

Q5. In the ‘Let’s Experiment’ activity, gram seeds are soaked in water for two days. What is the best explanation for why the outer covering of the seed swells up?

Correct Answer: (B) Water enters through the seed hole and is absorbed, causing the covering to swell

Explanation: Water enters the seed through the seed hole and is absorbed by the seed’s tissues. This absorption of water makes the outer covering (seed coat) swell and soften, preparing the seed for germination.

Q6. Lotus seeds are able to float and disperse on water mainly because of which feature?

Correct Answer: (C) Porous parts in the seed that trap air

Explanation: Lotus seeds have porous parts that trap air, giving them buoyancy. This allows them to float on water and be carried to new locations, unlike heavy, non-porous seeds that would sink.

Q7. A floating coconut can travel long distances across the sea before its seed germinates on a new shore. Which feature of the coconut seed makes this possible?

Correct Answer: (A) A spongy, fibrous covering that helps it float

Explanation: The coconut has a fibrous, spongy covering around its seed. This traps air and reduces its density, allowing it to float on water and be carried by currents to distant shores for dispersal.

Q8. Both dandelion and maple seeds are dispersed by wind, but they use different features to do so. Which statement correctly matches each plant with its wind-dispersal feature?

Correct Answer: (B) Dandelion has fine hair around its seeds; maple seeds have wings

Explanation: Dandelion seeds have fine hair around them, letting them float and drift in the breeze, while maple seeds have wing-like structures that let them spin and glide through the air. Both are light enough for wind dispersal, but the structures differ.

Q9. Which of these seeds is best adapted to spin and glide away from the parent plant when caught by the wind?

Correct Answer: (B) Maple seed

Explanation: Maple seeds have wing-like structures that make them spin as they fall, allowing wind to carry them further away from the parent tree, unlike cocklebur (dispersed by animals), coconut (water), or pea (explosion).

Q10. Balsam and pea plants disperse their seeds mainly through which method?

Correct Answer: (C) Dispersal by explosion

Explanation: In balsam and pea plants, the ripe fruit (pod) suddenly bursts open, scattering the seeds away from the parent plant with force. This is called dispersal by explosion.

Q11. The seeds of cocklebur are dispersed by animals. What feature of the cocklebur seed makes this possible?

Correct Answer: (B) Hooks or spikes that stick to fur or clothing

Explanation: Cocklebur seeds have hooks/spikes on their surface that stick to the fur of animals (or clothes of humans). The seeds are then carried to new places and eventually fall off, achieving dispersal.

Q12. Why is dispersal of seeds away from the parent plant important for the survival of a new plant?

Correct Answer: (B) It reduces competition with the parent plant for sunlight, water, nutrients and space

Explanation: If all seeds fell and grew right under the parent plant, the young plants would have to compete with the parent (and each other) for sunlight, water, nutrients and space. Dispersal allows seeds to reach new areas where they can grow with less competition.

Q13. Which of the following correctly shows the order of the stages of germination in a seed?

Correct Answer: (B) Seed gets water, air and warmth → seed coat breaks and baby plant grows → roots and shoot develop → young plant grows and leaves develop

Explanation: Germination begins only after the seed receives water, air and warmth. This causes the seed coat to break so the baby plant (embryo) can grow; roots emerge and grow downward first, then the shoot grows upward, and finally leaves develop.

Q14. During germination, which part of the young seedling typically grows downward into the soil first?

Correct Answer: (C) The root

Explanation: As stated in the germination process, the root comes out first and grows downward into the soil to anchor the seedling and absorb water, before the shoot grows upward towards sunlight.

Q15. Just after germination begins, before true leaves have formed, from where does the tiny seedling mainly get its food?

Correct Answer: (C) From the cotyledons

Explanation: In the early stages of germination, the seedling has not yet developed leaves to carry out photosynthesis, so it depends on the food stored in the cotyledons for its nourishment.

Q16. The method of growing new plants from vegetative parts such as roots, stems and leaves (instead of seeds) is called:

Correct Answer: (C) Vegetative propagation

Explanation: Roots, stems and leaves are called vegetative parts of a plant. When new plants are grown directly from these parts rather than from seeds, the process is called vegetative propagation.

Q17. New plants can grow directly from the roots of which group of plants?

Correct Answer: (B) Carrot, sweet potato, turnip, radish and dahlia

Explanation: Carrot, sweet potato, turnip, radish and dahlia store food in their roots, and new plants can grow from these roots — for example, a new plant grows from the root of a sweet potato, as shown in the experiment.

Q18. A potato can grow into a new plant from a small part of its surface called an ‘eye’. What exactly is this ‘eye’?

Correct Answer: (B) A bud on the underground stem

Explanation: Potato is an underground stem, and the ‘eyes’ on its surface are actually buds. Any part of the potato bearing an eye (bud) can grow into a new plant, which is why potato is grown by planting eyed pieces, not seeds.

Q19. Bryophyllum and Begonia are able to grow new plants from which vegetative part?

Correct Answer: (C) Buds on the margins of their leaves

Explanation: Bryophyllum (and Begonia) have small buds on the edges (margins) of their leaves. When such leaves are kept on moist soil, these buds develop into new plants — this is reproduction through leaves.

Q20. Rose, Hibiscus and money plant are commonly grown as new plants using which method?

Correct Answer: (A) Stem cutting

Explanation: A piece of stem (with a bud) cut from these plants, called a stem cutting, can be planted in soil where it develops roots and grows into a new plant. The original plant is called the mother plant.

Q21. Ferns reproduce through spores. Where on the fern plant are these spores usually found?

Correct Answer: (B) On the underside of the leaves

Explanation: Ferns do not produce seeds; instead, their spores are found on the underside of their leaves. These spores are released and can grow into new fern plants under suitable conditions.

Q22. Apart from ferns, which other living things mentioned in the chapter also reproduce through spores?

Correct Answer: (C) Fungi like mushroom and bread mould

Explanation: Along with ferns, fungi such as mushroom and bread mould also reproduce through spores rather than seeds. Spores are tiny reproductive structures that can develop into new organisms.

Q23. The practice of growing plants on a large scale for food and other purposes is known as:

Correct Answer: (C) Agriculture

Explanation: Agriculture is defined as the practice of growing plants (crops) on a large scale for food and other purposes. It has been practised in India since ancient times and involves several planned steps.

Q24. In the standard steps of agriculture (ploughing, manuring, sowing, irrigation, spraying pesticides, harvesting), which step comes immediately after sowing?

Correct Answer: (C) Irrigation

Explanation: After seeds are sown, the grown plants need irrigation — supplying water to the field through pipes or channels — so that the crop can grow well, before pesticides are sprayed and the crop is later harvested.

Q25. Rice, maize and cotton are examples of kharif crops. What does this indicate about how and when they are grown?

Correct Answer: (B) They are grown from June to October and depend on monsoon rains

Explanation: Kharif crops such as rice, maize and cotton are sown around the start of the monsoon and grown from June to October, relying heavily on monsoon rains for water.

 

Topics covered: Seed structure • Dispersal of seeds • Germination • Vegetative propagation • Reproduction through spores • Agriculture & crops