UPSC Prelims 2014 Q17: Science & Technology – Biology
Consider the following :
1. Bats
2. Bears
3. Rodents
The phenomenon of hibernation can be observed
in which of the above kinds of animals?
- (a) 1 and 2 only
- (b) 2 only
- (c) 1, 2 and 3
- (d) Hibernation cannot be observed in any of the above
Answer: (c) 1, 2 and 3
Explanation
Hibernation
Hibernation is a long winter sleep in which an animal's body temperature, heartbeat and breathing fall, to save energy when food is scarce.
| Animal | Hibernates? | Note |
|---|---|---|
| 1. Bats | Yes | Many species of cold regions hibernate in caves |
| 2. Bears | Yes | A lighter winter sleep; body temperature falls only a little |
| 3. Rodents | Yes | Ground squirrels, marmots, dormice are classic hibernators |
Related terms:
| Term | Meaning |
|---|---|
| Hibernation | Winter sleep |
| Aestivation | Summer sleep, to escape heat and drought (snails, lungfish) |
| Torpor | Short daily drop in body activity |
| Diapause | Halted development in insects and zooplankton |
Answer: (c) 1, 2 and 3.
Why each option is right or wrong
- (a) Incorrect. Rodents such as marmots and ground squirrels also hibernate.
- (b) Incorrect. Bats and rodents hibernate too, not bears alone.
- (c) CORRECT. Hibernation is seen in bats, bears and rodents.
- (d) Incorrect. All three kinds of animals show hibernation.
Key point
Hibernation = winter sleep (bats, bears, rodents such as marmots). Aestivation = summer sleep (snails, lungfish).
Remember
Bats, bears and rodents all hibernate.
Common mistakes
- Thinking only bears hibernate; many small mammals do too.
- Confusing hibernation (winter) with aestivation (summer).
- Assuming flying mammals such as bats cannot hibernate.
Exam tip
H for hibernation and 'hiver' (winter); A for aestivation and arid summer.
Sources
- NCERT Class XII — Biology (Organisms and Populations: responses to abiotic factors)
- NCERT Class XI — Biology (Animal Kingdom: Mammalia)