Q. Which of the following animals are poikilotherms?

1. Fish
2. Insects
3. Birds
4. Crocodile

Select the correct answer using the codes given below:
Answer: Only 1, 2 & 4
Notes: Poikilotherms (cold-blooded animals) are those whose body temperature varies with the environment. Fish, insects, and reptiles (like crocodiles) are poikilotherms. Birds, along with mammals, are homeotherms (warm-blooded) and maintain a constant internal temperature. Thus, options 1, 2, and 4 are correct, while birds (option 3) are not poikilothermic.