NSO Class 5 Science Reproduction in Plants Olympiad MCQs with Answers
Section A: Olympiad-Level MCQs
- Which part of a seed mainly protects the baby plant from injury and drying?
(A) Cotyledon
(B) Seed coat
(C) Embryo
(D) Seed hole
- A soaked gram seed is split into two halves. A tiny structure is seen between the two cotyledons. What is this structure?
(A) Seed coat
(B) Embryo
(C) Seed hole
(D) Spore
- Why are cotyledons important during the early stages of germination?
(A) They scatter the seed
(B) They store food for the developing baby plant
(C) They make the seed waterproof
(D) They form flowers immediately
- A seed is placed in moist soil but kept in a refrigerator. It does not germinate well. Which requirement is mainly missing?
(A) Air
(B) Water
(C) Warmth
(D) Cotyledons
- Which sequence correctly represents germination?
(A) Leaves form → seed coat swells → roots develop → seed gets water
(B) Seed gets water and warmth → seed coat swells → roots and shoot develop → leaves develop
(C) Roots develop → seed gets water → leaves develop → seed coat swells
(D) Seed coat swells → leaves develop → seed gets water → roots develop
- A very light seed has fine hair-like structures. Which method of dispersal is it best adapted for?
(A) Water
(B) Wind
(C) Animals
(D) Explosion
- Which pair shows adaptations for the SAME method of seed dispersal?
(A) Dandelion and winged maple
(B) Coconut and cocklebur
(C) Balsam and lotus
(D) Pea and coconut
- A fruit has a fibrous, spongy covering that helps it float. Which plant is most likely to have such a fruit?
(A) Balsam
(B) Coconut
(C) Cocklebur
(D) Dandelion
- Lotus seeds can be carried by water mainly because the fruit has:
(A) Hooks that attach to animals
(B) A spongy, porous part that helps it float
(C) Hair-like structures
(D) A pod that bursts
- Which observation gives the strongest evidence for dispersal by animals?
(A) A seed has a wing
(B) A fruit floats
(C) A seed has hooks or spikes
(D) A pod dries and bursts
- Pea and balsam seeds are dispersed when their fruits suddenly burst open. This method is called:
(A) Dispersal by wind
(B) Dispersal by water
(C) Dispersal by animals
(D) Dispersal by explosion
- Why is seed dispersal generally useful to a plant?
(A) It keeps all seedlings under the parent plant
(B) It reduces competition for space, light, water and nutrients
(C) It prevents all seeds from germinating
(D) It changes seeds into spores
- Which of the following is an example of vegetative propagation through a root?
(A) Potato
(B) Sweet potato
(C) Bryophyllum
(D) Rose
- A potato ‘eye’ can grow into a new potato plant because the eye is:
(A) A root hair
(B) A seed hole
(C) A bud on an underground stem
(D) A spore case
- A gardener places a piece of rose stem with a bud into moist soil. After some days it develops roots and shoots. This is:
(A) Seed dispersal
(B) Stem cutting
(C) Spore formation
(D) Pollination
- Which plant can produce new plants from buds present along the edges of its leaves?
(A) Wheat
(B) Bryophyllum
(C) Pea
(D) Carrot
- Ferns differ from rose plants in one important method of reproduction. Ferns commonly reproduce through:
(A) Spores
(B) Stem cuttings only
(C) Fruit explosion
(D) Underground roots only
- Which set contains only examples of vegetative plant parts used for reproduction?
(A) Roots, stems and leaves
(B) Flowers, fruits and seeds
(C) Cotyledons, seed coat and embryo
(D) Pollen, fruit and spores
- A farmer adds manure before sowing. What is the main purpose of this step?
(A) To remove mature crops
(B) To enrich the soil with nutrients
(C) To scatter seeds by wind
(D) To stop irrigation
- Which agricultural step should normally occur immediately BEFORE sowing?
(A) Harvesting
(B) Spraying pesticides
(C) Manuring
(D) Irrigation after crop growth
- What is the main advantage of ploughing the field before sowing?
(A) It cuts and gathers the crop
(B) It loosens the soil
(C) It kills every organism in the soil
(D) It turns rabi crops into kharif crops
- A crop is sown in June and harvested around October, depending mainly on monsoon rains. It is most likely a:
(A) Rabi crop
(B) Kharif crop
(C) Winter crop only
(D) Vegetatively propagated crop
- Which group contains only kharif crops mentioned in the chapter?
(A) Wheat, gram, pea
(B) Rice, maize, cotton
(C) Wheat, rice, pea
(D) Gram, cotton, wheat
- Which statement correctly compares rabi and kharif crops?
(A) Both depend mainly on monsoon rains
(B) Rabi crops are generally grown November–April, while kharif crops are generally grown June–October
(C) Kharif crops are grown only from roots
(D) Rabi crops cannot be irrigated
- A student wants to test whether water is necessary for germination. Which setup gives the fairest comparison?
(A) Use two different kinds of seeds in different temperatures
(B) Keep identical seeds under the same warmth and air conditions, but give water to only one group
(C) Give one group water and sunlight and keep the other group cold and dry
(D) Use one seed in soil and another potato eye in water
Class 5 Science Reproduction in Plants Olympiad MCQs Answer Key with Explanations
- Answer: (B) Seed coat
Explanation: The seed coat is the outer covering of a seed. It protects the embryo, or baby plant, from damage and drying.
- Answer: (B) Embryo
Explanation: The embryo is the baby plant present inside the seed. In gram, it lies between the two cotyledons.
- Answer: (B) They store food for the developing baby plant
Explanation: Cotyledons store food that nourishes the embryo until the young plant can make enough food through its leaves.
- Answer: (C) Warmth
Explanation: Seeds need suitable warmth, along with water and air, for germination. Very low temperature can prevent proper germination.
- Answer: (B) Seed gets water and warmth → seed coat swells → roots and shoot develop → leaves develop
Explanation: During germination, the seed first absorbs water and gets suitable warmth; the coat swells, the root and shoot emerge, and later leaves develop.
- Answer: (B) Wind
Explanation: Light seeds with hairs or wing-like structures can be carried easily by moving air, so they are dispersed by wind.
- Answer: (A) Dandelion and winged maple
Explanation: Dandelion has fine hairs and maple has wing-like structures; both help seeds travel through the air.
- Answer: (B) Coconut
Explanation: Coconut has a fibrous covering that helps the fruit float and be carried by water currents.
- Answer: (B) A spongy, porous part that helps it float
Explanation: The lotus fruit has a porous, spongy structure that allows it to float on water.
- Answer: (C) A seed has hooks or spikes
Explanation: Hooks and spikes can cling to animal fur or clothing, allowing the seeds to be carried to new places.
- Answer: (D) Dispersal by explosion
Explanation: In pea and balsam, the ripe fruit or pod bursts and throws the seeds away from the parent plant.
- Answer: (B) It reduces competition for space, light, water and nutrients
Explanation: Dispersal spreads seeds away from the parent plant, reducing overcrowding and competition for essential resources.
- Answer: (B) Sweet potato
Explanation: Sweet potato is an underground root that stores food and can produce a new plant. Potato is a stem, Bryophyllum uses leaves, and rose can grow from stem cuttings.
- Answer: (C) A bud on an underground stem
Explanation: Potato is an underground stem. Its eyes are buds capable of developing into new shoots and plants.
- Answer: (B) Stem cutting
Explanation: Rose can reproduce vegetatively through stem cuttings. A stem piece with a bud can form roots and grow into a new plant.
- Answer: (B) Bryophyllum
Explanation: Bryophyllum has buds along the leaf margins. These buds can grow into new plants when conditions are suitable.
- Answer: (A) Spores
Explanation: Ferns produce spores, often found on the underside of their leaves, and these spores can grow into new plants.
- Answer: (A) Roots, stems and leaves
Explanation: Vegetative propagation uses non-seed plant parts such as roots, stems and leaves.
- Answer: (B) To enrich the soil with nutrients
Explanation: Manuring adds natural or chemical nutrients to the soil, improving fertility and supporting plant growth.
- Answer: (C) Manuring
Explanation: The chapter gives the sequence as ploughing, manuring, sowing, irrigation, spraying pesticides and harvesting.
- Answer: (B) It loosens the soil
Explanation: Ploughing turns and loosens the soil, making it more suitable for sowing and root growth.
- Answer: (B) Kharif crop
Explanation: Kharif crops are generally grown from June to October and depend strongly on monsoon rainfall.
- Answer: (B) Rice, maize, cotton
Explanation: Rice, maize and cotton are listed as kharif crops, whereas wheat, gram and pea are rabi crops.
- Answer: (B) Rabi crops are generally grown November–April, while kharif crops are generally grown June–October
Explanation: The chapter identifies rabi crops as winter-season crops grown roughly November to April and kharif crops as monsoon-season crops grown roughly June to October.
- Answer: (B) Keep identical seeds under the same warmth and air conditions, but give water to only one group
Explanation: A fair test changes only one factor. Keeping seed type, warmth and air the same while changing only water tests the role of water in germination.
Topics covered: structure of seeds, germination, seed dispersal, vegetative propagation, reproduction through spores, agriculture, steps of agriculture, and rabi/kharif crops.