Select an incorrect statement about stomata

Options

A. number of such tiny pores varies from 10 to 60 per cm2 of the leaf surface.
B. in grasses the stomatal density is almost the same on both the surfaces of leaf.
C. guard cells are special types of epidermal cells
D. size of a typical stomatal pore ranges from 3-12 um in width and from 10-14 um in length.

Answer

### Step-by-Step Solution:

1. **Understanding Stomata**: Stomata are tiny pores located on the epidermal layer of leaves. Their primary function is to facilitate gaseous exchange and water loss in plants.

2. **Guard Cells**: Each stomatal pore is surrounded by specialized cells known as guard cells. These cells regulate the opening and closing of the stomata.

3. **Stomatal Size**: The size of a typical stomatal pore ranges from 3 to 12 micrometers (μm) in width and 10 to 14 μm in length.

4. **Stomatal Density**: The number of stomata per square centimeter of leaf can vary significantly, typically ranging from 1,000 to 60,000 stomata per square centimeter.

5. **Analyzing the Options**:
- **Option 1**: "The number of such tiny pores varies from 10 to 60 per centimeter square of leaf." This statement is incorrect because the actual range is 1,000 to 60,000 stomata per square centimeter.
- **Option 2**: "In grasses, the stomatal density is almost the same on both surfaces of the leaf." This statement is generally true for many grasses.
- **Option 3**: "Guard cells are specialized epidermal cells." This statement is true as guard cells are indeed a type of epidermal cell.
- **Option 4**: "The size of a typical stomatal pore ranges from 3 to 12 μm in width." This statement is also true.

6. **Conclusion**: The incorrect statement about stomata is the first option, which inaccurately states the number of stomata per square centimeter.