Define fertilization.

Explanation

### Step-by-Step Text Solution for the Definition of Fertilization:

1. **Introduction to Fertilization**: Fertilization is a biological process that involves the fusion of gametes, which are the reproductive cells from two parents.

2. **Types of Gametes**: In humans, there are two types of gametes:
- **Male Gametes**: These are called sperm and are produced by the male reproductive system.
- **Female Gametes**: These are known as ova (or eggs) and are produced by the female reproductive system.

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