UPSC Prelims 2013 Q91: Science & Technology – Biology
Many transplanted seedlings do not grow because
- (a) the new soil does not contain favourable minerals
- (b) most of the root hairs grip the new soil too hard
- (c) most of the root hairs are lost during transplantation
- (d) leaves get damaged during transplantation
Answer: (c) most of the root hairs are lost during transplantation
Explanation
Why many transplanted seedlings fail
A plant takes in water and minerals through its root hairs.
These are fine, delicate outgrowths of the root's surface cells.
When a seedling is pulled out, most root hairs break off and stay in the old soil.
| Option | Verdict | Reason |
|---|---|---|
| (a) The new soil does not contain favourable minerals | Incorrect | Not the usual reason |
| (b) Most of the root hairs grip the new soil too hard | Incorrect | They are mostly gone |
| (c) Most of the root hairs are lost during transplantation | Correct | The plant cannot absorb water and wilts |
| (d) Leaves get damaged during transplantation | Incorrect | Not the main cause |
How gardeners reduce the loss:
| Practice | Why |
|---|---|
| Lift with a ball of soil | Keeps root hairs intact |
| Transplant in the evening | Less water loss through leaves |
| Trim some leaves | Cuts transpiration |
| Water at once | Helps new root hairs grow |
Answer: (c) most of the root hairs are lost during transplantation.
Why each option is right or wrong
- (a) Incorrect. Lack of minerals in the new soil is not the usual cause.
- (b) Incorrect. Root hairs do not grip too hard; they are lost.
- (c) CORRECT. Most root hairs are lost, so the seedling cannot take up water.
- (d) Incorrect. Damage to leaves is not the main reason.
Key point
Root hairs absorb water and minerals; they break off in transplanting, causing wilting ('transplant shock'). Move seedlings with a ball of soil.
Remember
Transplant failure = lost root hairs.
Common mistakes
- Blaming the new soil instead of root damage.
- Forgetting that root hairs, not thick roots, do the absorbing.
- Not linking wilting to transpiration exceeding water uptake.
Exam tip
No root hairs, no water. That is transplant shock.
Sources
- NCERT Class XI — Biology (Morphology of Flowering Plants; Transport in Plants)
- Indian Council of Agricultural Research — Nursery management and transplanting practices