Choose the CORRECT statement from the following.

Options

A. Stomata opens when guard cells become turgid
B. Stomata opens when guard cells become flaccid
C. Stomata opens when guard cells become turgid and flaccid
D. Stomata close when guard cells become turgid

Answer

To solve the question, we need to analyze the statements regarding the behavior of stomata and guard cells. Here’s the step-by-step solution:

### Step 1: Understand the Function of Stomata
Stomata are small openings on the surface of leaves that allow for gas exchange (CO2 and O2) and transpiration (loss of water vapor).

**Hint:** Remember that stomata play a crucial role in photosynthesis and respiration by allowing gases to enter and exit the leaf.

### Step 2: Identify the Role of Guard Cells
Guard cells are specialized cells that surround each stoma. They control the opening and closing of the stomata by changing their turgidity (the state of being swollen or distended due to water).

**Hint:** Think of guard cells as the "valves" that open and close the stomata based on water availability.

### Step 3: Mechanism of Opening and Closing
- When guard cells take up water, they become turgid (swollen), causing the stomata to open.
- When guard cells lose water, they become flaccid (soft), causing the stomata to close.

**Hint:** Associate turgidity with opening and flaccidity with closing of stomata.

### Step 4: Analyze Each Statement
1. **Stromata opens when guard cells become turgid** - This statement is correct.
2. **Stromata opens when guard cells become flaccid** - This statement is incorrect; stomata close when guard cells are flaccid.
3. **Stromata opens when guard cells become turgid and flaccid** - This statement is incorrect; stomata cannot be open and closed at the same time.
4. **Stromata closes when guard cells become turgid** - This statement is incorrect; stomata open when guard cells are turgid.

**Hint:** Evaluate each statement based on the relationship between guard cell turgidity and the state of the stomata.

### Step 5: Choose the Correct Statement
Based on the analysis, the correct statement is: **Stromata opens when guard cells become turgid.**

**Final Answer:** The correct statement is the first one.