In gymnosperms, how many male gametes are produced by each pollen grain ?
(a) 4
(b) 3
(c) 2
(d) 1

Options

A. (a) 4
B. 3
C. 2
D. 1

Answer

To answer the question "In gymnosperms, how many male gametes are produced by each pollen grain?", we can follow these steps:

1. **Understanding Pollen Grain Development**: Pollen grains in gymnosperms develop from microspores, which are produced by microsporocytes (male sporocytes).

2. **Cell Stages of Pollen Grains**: The microspores can develop into pollen grains that can be in a 3-celled, 4-celled, or even 5-celled stage.

3. **Mitosis in Microspores**: Upon maturation, the microspore undergoes mitosis. This process produces two types of nuclei: a generative nucleus and a tube nucleus.

4. **Formation of Male Gametes**: The generative nucleus further divides to produce two male gametes (also referred to as antherozoids). The tube nucleus does not divide further; it helps in the formation of the pollen tube.

5. **Conclusion**: Therefore, each pollen grain in gymnosperms ultimately produces **two male gametes**.

Thus, the correct answer to the question is **(c) 2**.