Which is not true for CAM plants?
(a) Scotoactive opening of stomata
(b) Dark acidification of cytoplasm
(c) Separation of cytoplasm
(d) Separation of Hatch-Slack and `O_(3)` cycle in time

Options

A. Scotoactive opening of stomata
B. Dark acidification of cytoplasm
C. Separation of cytopasm
D. Separation of Hatch-Slack and `O_(3)` cycle in time

Answer

To determine which statement is not true for CAM (Crassulacean Acid Metabolism) plants, let's analyze each option step by step:

1. **Understanding CAM Plants**: CAM plants are adapted to arid environments and have a unique photosynthetic pathway that allows them to conserve water. They open their stomata at night to take in carbon dioxide (CO2) and close them during the day to minimize water loss.

2. **Evaluating Option A: Scotoactive opening of stomata**:
- CAM plants exhibit scotoactive stomatal opening, meaning they open their stomata at night (scotoperiod) when it is cooler and more humid. This statement is true.

3. **Evaluating Option B: Dark acidification of cytoplasm**:
- During the night, when CAM plants take in CO2, it is converted into organic acids, leading to a decrease in pH (acidification) in the cytoplasm. This process is known as dark acidification. This statement is true.

4. **Evaluating Option C: Separation of cytoplasm**:
- This statement is somewhat vague but can refer to the compartmentalization of processes in CAM plants. In CAM plants, the initial fixation of CO2 occurs at night, and the subsequent processing occurs during the day. This separation of processes is a characteristic of CAM plants. Therefore, this statement can also be considered true.

5. **Evaluating Option D: Separation of Hatch-Slack and O3 cycle in time**:
- The Hatch-Slack pathway (C4 pathway) and the Calvin cycle (often referred to as the O3 cycle in this context) are indeed separated in time in CAM plants. During the night, CO2 is fixed into organic acids, and during the day, these acids are converted back to CO2 for the Calvin cycle. This statement is true.

6. **Conclusion**: All options A, B, C, and D are true regarding CAM plants. However, the question asks for the statement that is not true. Upon careful analysis, the most misleading or incorrect statement is **Option C: Separation of cytoplasm**, as it does not accurately reflect the distinct processes that occur in CAM plants compared to the other options. Therefore, the answer is **C**.

### Final Answer:
**(c) Separation of cytoplasm**