What can be various causes of infertility?

Explanation

### Step-by-Step Solution:

1. **Definition of Infertility**: Infertility is defined as the inability of a couple to conceive after a prolonged period of unprotected sexual intercourse. This can be due to various factors affecting either the male or female reproductive systems.

2. **Role of Gametes**: For conception to occur, both male and female gametes (sperms and ova) must be produced and function properly. Any issues in gametogenesis can lead to infertility.

3. **Male Factors**:
- **Sperm Production**: Infertility in males can arise from low sperm count or inadequate production of sperm.
...