The number of nuclei present in a zygote is :

Options

A. none
B. one
C. two
D. four

Answer

To determine the number of nuclei present in a zygote, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of a Zygote**:
- A zygote is the initial cell formed when a male gamete (sperm) fertilizes a female gamete (egg).

2. **Identify the Process of Fertilization**:
- Fertilization is the process where the male and female gametes fuse together. This fusion results in the formation of a single cell, the zygote.

3. **Determine the Chromosome Composition**:
- In humans and many other organisms, the male and female gametes are haploid, meaning they each contain one set of chromosomes (N). When they fuse, they form a diploid zygote (2N), which contains two sets of chromosomes.

4. **Count the Number of Nuclei**:
- Despite the zygote being diploid and containing two sets of chromosomes, it is still a single cell. Therefore, it has only one nucleus.

5. **Conclusion**:
- The number of nuclei present in a zygote is 1.

### Final Answer:
The number of nuclei present in a zygote is **1**.

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