Stomata which opens up in night and remains close during day time shows

Options

A. `C_3` pathway
B. CAM pathway
C. `C_4` pathway
D. Both (B) and (C)

Answer

To solve the question regarding the type of stomatal behavior described, we can follow these steps:

### Step 1: Understand the Stomatal Behavior
The question states that the stomata open at night and close during the day. This is a specific adaptation seen in certain plants.

**Hint:** Consider the environmental conditions that might lead a plant to adopt this behavior.

### Step 2: Identify the Purpose of This Adaptation
Plants that open their stomata at night do so primarily to reduce water loss through transpiration during the hotter daytime hours. This adaptation is crucial for survival in arid environments.

**Hint:** Think about how water conservation is vital for plants in dry habitats.

### Step 3: Review the Photosynthetic Pathways
The question provides options related to different photosynthetic pathways:
- **C3 Pathway:** Typical for most plants, where stomata are open during the day.
- **C4 Pathway:** Involves two types of cells and is also active during the day.
- **CAM Pathway:** Stands for Crassulacean Acid Metabolism, where stomata open at night.

**Hint:** Recall which plants are known for opening their stomata at night and how they perform photosynthesis.

### Step 4: Determine the Correct Pathway
Given the options, the CAM pathway is specifically designed for plants in arid conditions. These plants, such as cacti and succulents, open their stomata at night to take in CO2 and close them during the day to minimize water loss.

**Hint:** Think about examples of plants that use this method and their adaptations to dry environments.

### Step 5: Conclusion
Based on the understanding of stomatal behavior and the characteristics of the different pathways, the correct answer to the question is the CAM pathway.

**Final Answer:** The stomata which open at night and remain closed during the day show the CAM pathway.