CAPF AC 2020 Q44: Environment & Ecology – Biodiversity & Conservation
Which one of the following statements about the Acacia tree is/are correct?
1. It has a long shallow root system which enables it to find moisture
2. It has thorny leaves to prevent water loss
3. It has wide crown so the foliage can absorb the maximum Sunlight
Select the correct answer using the code given below:
- (a) 1 only
- (b) 2 and 3 only
- (c) 1 and 2 only
- (d) 1, 2 and 3
Answer: (d) 1, 2 and 3
Explanation
How the Acacia tree survives in dry lands
How to think: Acacia grows in hot, dry savanna and semi-desert.
Every feature should help it get water, save water or use sunlight.
Check each statement against that.
| Statement | Verdict | How it helps |
|---|---|---|
| 1. It has a long shallow root system which enables it to find moisture | Correct | Roots spread far near the surface and catch rain before it dries |
| 2. It has thorny leaves to prevent water loss | Correct | Small leaves and thorns lose little water and keep grazing animals away |
| 3. It has wide crown so the foliage can absorb the maximum Sunlight | Correct | The flat umbrella-shaped top spreads the leaves out |
Plants of dry regions:
| Feature | Purpose |
|---|---|
| Small or needle-like leaves | Less water lost |
| Thick bark | Protects from heat and fire |
| Long or wide roots | Reach more water |
All three statements are accepted in the official answer key.
Answer: (d) 1, 2 and 3.
Why each option is right or wrong
- (a) Incorrect. Statement 1 is right, but statements 2 and 3 are right as well.
- (b) Incorrect. This leaves out statement 1 on the root system, which is also right.
- (c) Incorrect. This leaves out statement 3 on the wide crown, which is also right.
- (d) CORRECT. Roots, thorny leaves and the wide crown are all adaptations of the Acacia.
Key point
Acacia (savanna tree): wide-spreading roots to find moisture, small thorny leaves to save water, umbrella-shaped crown to catch sunlight.
Remember
Acacia: wide roots, thorny leaves, umbrella crown.
Common mistakes
- Doubting statement 1 because desert plants are known for deep roots; Acacia also spreads roots wide.
- Thinking thorns are only for defence; they also cut water loss.
- Placing Acacia in rainforests; it is a tree of savanna and dry scrub.
Exam tip
Educated guess: when every statement describes a sensible way to cope with dryness, all of them are likely right.
Sources
- NCERT Class XI Geography — India: Physical Environment (Natural Vegetation: tropical thorn forests)
- UPSC — CAPF (ACs) Examination 2020, Paper I (official answer key)