Read the following four statements ( A -D ):
(i) The outer wall of the pollen grain is pecto - cellulosic in nature.
(ii) In pollen grain, the generative cell is bigger and contains abundant food reserve.
(iii) In all angiosperm , pollen grains are always shed at the 2-celled stage.
(iv) Usually , sporogenous cell directly behaves as the megaspore mother cell.
How many of the above statements are wrong ?

Options

A. Four
B. One
C. Two
D. Three

Answer

To determine how many of the provided statements about pollen grains are wrong, let's analyze each statement one by one:

### Step-by-Step Solution:

1. **Statement A**: "The outer wall of the pollen grain is pecto-cellulosic in nature."
- **Analysis**: The outer layer of the pollen grain is known as the exine, which is primarily composed of sporopollenin, not pecto-cellulosic material. Therefore, this statement is **wrong**.

2. **Statement B**: "In pollen grain, the generative cell is bigger and contains abundant food reserve."
- **Analysis**: In a mature pollen grain, the vegetative cell is larger than the generative cell, and the vegetative cell contains the food reserves. Thus, this statement is also **wrong**.

3. **Statement C**: "In all angiosperms, pollen grains are always shed at the 2-celled stage."
- **Analysis**: While many angiosperms do shed their pollen at the 2-celled stage, a significant percentage (about 40%) shed pollen at the 3-celled stage, where the generative cell divides to form two male gametes. Therefore, this statement is **wrong**.

4. **Statement D**: "Usually, sporogenous cell directly behaves as the megaspore mother cell."
- **Analysis**: The sporogenous tissue is involved in microsporogenesis, leading to the formation of microspores, not megaspores. The megaspore mother cell is a different entity involved in megasporogenesis. Thus, this statement is also **wrong**.

### Conclusion:
All four statements (A, B, C, and D) are incorrect. Therefore, the answer to the question is that **4 statements are wrong**.