In dicots, at how many places exine is absent in the pollen grain ?
(a) 2
(b) 3
(c) 1
(d) more than 3

Options

A. 2
B. 3
C. 1
D. more than 3

Answer

To solve the question regarding the absence of exine in the pollen grain of dicots, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Pollen Grain**:
- Pollen grains consist of two layers: the exine (outer layer) and the intine (inner layer). The exine is made up of sporopollenin, which provides protection.

2. **Identify the Characteristics of Exine in Dicots**:
- In dicots, the exine is typically absent at specific locations. These locations are referred to as germ pores.

3. **Count the Germ Pores**:
- In dicots, there are three distinct areas where the exine is absent, which allows for the emergence of the pollen tube and the release of male gametes.

4. **Recognize the Terminology**:
- The condition of having three germ pores in dicots is termed "tricolpate."

5. **Evaluate the Options Provided**:
- The options given are:
- (a) 2
- (b) 3
- (c) 1
- (d) more than 3
- Since we identified that the exine is absent at three locations, the correct answer is (b) 3.

### Final Answer:
The correct answer is (b) 3.

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