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NCERT Solutions Curiosity Chapter 10 .2 — In-text Questions

Book page 19010 Updated on2026-09-05

Q1.
Do you think sunlight is necessary for germination of seeds?
Answer

No — sunlight is not necessary for the germination of bean seeds.

The evidence: Pot C was kept in complete darkness with moist soil, and the seeds in it germinated. Only water and air were available, and that was enough.

Pot C: air ✓   water ✓   sunlight ✗  →  germination happened

The book states the general rule: most seeds do not require light for germination. But after germination, sunlight is required for the further growth of the seedling — that is why the Pot C seedlings were pale and weak while those in Pot D were green and sturdy.

Did you know? There are exceptions in both directions. Seeds of Coleus and Petunia need light to germinate, so covering them with soil stops them from sprouting. Seeds of Calendula and Zinnia need darkness, so they must be covered with enough soil.
Q2.
Do the seeds in all the pots receive air, water and sunlight? Is there any pot in which air is not available to the seeds? If so, why is it not available?
Answer

No, no pot except D received all three in the right amounts.

  • Pot A — air and sunlight, but no water.
  • Pot B — sunlight and plenty of water, but no air.
  • Pot C — air and water, but no sunlight.
  • Pot D — air, water and sunlight, all in the right amount.

The pot in which air is not available is Pot B.

Why air is missing there: normal soil is not solid — there are countless tiny spaces between the soil particles, and these spaces are full of air. That is the air the seed uses. In Pot B water is kept standing above the soil all the time, so it seeps into every one of those spaces and pushes the air out. The seed then sits in waterlogged soil with no air to respire, and it rots instead of sprouting.
Where you see this outside the classroom: after very heavy rain, a field where water stands for several days turns yellow and the young plants die. Farmers cut drainage channels for exactly this reason — to let the air back into the soil.
Q3.
What happens to the seeds in the pot where water is provided in excess?
Answer

They do not germinate. They swell up, become soft, turn dark, start to rot and give off a bad smell.

Excess water → soil spaces filled → no air for the seed → seed cannot respire → seed decays

Two things happen together:

  • The seed cannot get the air it needs to release energy, so the embryo dies.
  • A dead, soft seed in warm wet soil is quickly attacked by moulds and bacteria, which is what makes it slimy and smelly.
Check it yourself: soak ten rajma seeds in a bowl of water and leave them fully under water for four days. Keep another ten on damp cotton. The soaked-under-water lot will smell sour and go soft; the ones on damp cotton will sprout. Same seeds, same water, different amount of air.
Q4.
Which seeds receive both air and water? Identify the pots where you can notice the germination of seeds.
Answer

The seeds in Pot C and Pot D receive both air and water.

PotAirWaterDid the seeds germinate?
AYesNoNo
BNoExcessNo
CYesYesYes — but the seedlings are pale and thin
DYesYesYes — healthy green seedlings

Germination is seen in Pots C and D — exactly the two pots that got both air and water. That is the answer the experiment was designed to produce.

How to read an experiment like this: line up the pots that gave the same result and see what they share. C and D both germinated, and the one thing they have in common is air + the right amount of water. A and B failed, and each of them is missing one of those two. Sunlight varies between C and D without changing the result — so sunlight is not the deciding factor.
Q5.
Based on your observations, state the conditions which favour seed germination. Which of the following are essential for seed germination – air, water and sunlight?
Answer

Conditions that favour germination: the right amount of water, enough air, and a suitable (warm) temperature. Sunlight is not essential.

Essential → Water (the right amount) + Air
Not essential for bean seeds → Sunlight
ConditionEssential?Which pot proves it
Water — in the right amountYesPot A had none and failed; too much in Pot B also failed
AirYesPot B had none and failed
SunlightNo (for bean seeds)Pot C had none and still germinated

In the book's own words: germination of bean seeds requires the right amount of water and air.

Tip: say “the right amount of water”, not just “water”. Both too little (Pot A) and too much (Pot B) stop germination — that is one of the neatest results in this chapter.
Q6.
Why do seeds require these conditions for germination? Do you think that the absence of one or more of these conditions will affect seed germination?
Answer

Each condition does a specific job, so yes — if even one is missing, germination is affected or stops altogether.

ConditionWhat it does for the seedIf it is absent
WaterSoftens the seed coat (the outer covering of the seed) so it can split, and enables the seed to carry out the processes necessary for growth. It helps the tiny embryo inside develop into a plant.The coat stays hard, the embryo stays dormant, nothing happens (Pot A)
AirSeeds use the air present in the spaces between soil particles to respire and release the energy needed for germination.The seed cannot respire; it rots (Pot B)
Soil with spacesBesides holding that air, the spaces between soil particles allow the roots to grow easily.Roots struggle in hard, compacted soil
Suitable temperatureThe life processes inside the seed work only in a moderate range of warmth.Too cold or too hot — germination is slow or does not occur
Light / darkNot needed for germination in most seeds, but sunlight is needed after germination for the seedling to grow.Seedlings become pale, thin and weak (Pot C)
Why this is exactly like a balanced diet: the chapter reminds you that human beings need a balanced diet for good health and proper growth. In the same way, plants need favourable conditions and nutrients. Neither a person nor a plant can manage with just one requirement supplied in plenty while another is missing.
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