Stomata open at night and close during day in
(a) succulents
(b) hydrophytes
(c) mesophytes
(d) epiphytes

Options

A. succulents
B. hydrophytes
C. mesophytes
D. epiphytes

Answer

To solve the question "Stomata open at night and close during day in:", we need to analyze the options provided and understand the characteristics of each type of plant.

### Step-by-Step Solution:

1. **Understanding Stomatal Behavior**:
- In most plants, stomata typically open during the day to allow for gas exchange (CO2 intake for photosynthesis) and close at night to reduce water loss.
- However, some plants have adapted to different environments and have unique stomatal behaviors.

2. **Identifying Plant Types**:
- **Succulents**: These are plants that store water in their leaves, stems, or roots. They often have a special adaptation where their stomata open at night (a process known as CAM - Crassulacean Acid Metabolism) to minimize water loss during the hot day.
- **Hydrophytes**: These are water-loving plants that live in aquatic environments. They typically have stomata that can open and close based on water availability, but they do not specifically open at night.
- **Mesophytes**: These plants thrive in moderate conditions and usually follow the typical stomatal behavior of opening during the day and closing at night.
- **Epiphytes**: These are plants that grow on other plants. They can have various stomatal behaviors depending on their environment, but they do not specifically open at night.

3. **Conclusion**:
- Based on the unique adaptation of succulents to open their stomata at night and close them during the day, the correct answer is **(a) succulents**.

### Final Answer:
**(a) succulents**

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