Diapause is exhibited by

Options

A. Insects
B. Embryos of some fishes
C. Zooplanktons in lake and ponds
D. all of above

Answer

**Step-by-Step Solution:**

1. **Understanding Diapause**: Diapause is a biological term that refers to a period of suspended development in organisms. It occurs in response to unfavorable environmental conditions.

2. **Identifying Organisms Exhibiting Diapause**: The question asks which organisms exhibit diapause. The options provided include:
- Embryos of some fishes
- Zooplankton in lakes and ponds
- All of the above

3. **Analyzing Each Option**:
- **Embryos of Some Fishes**: Certain fish embryos can enter a diapause stage to survive harsh conditions. They may develop a protective covering to withstand environmental stress.
- **Zooplankton in Lakes and Ponds**: Zooplankton can also undergo diapause, where they reduce their metabolic activity and may form cysts to survive unfavorable conditions like extreme temperatures or lack of food.

4. **Conclusion**: Since both embryos of some fishes and zooplankton exhibit diapause, the correct answer is "All of the above."

5. **Final Answer**: Diapause is exhibited by all of the above options.

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