Genes do not occur in pairs in

Options

A. Zygote
B. Somatic cell
C. Endosperm cells
D. Gametes

Answer

**Step-by-step Solution:**

1. **Understanding the Question**: The question asks where genes do not occur in pairs. To answer this, we need to understand the genetic composition of different cell types.

2. **Identifying the Options**: The options provided are:
- Zygote
- Somatic cells
- Endosperm cells
- Gametes

3. **Analyzing Each Option**:
- **Zygote**: A zygote is formed when two gametes fuse during fertilization. Zygotes are diploid (2n), meaning they contain pairs of chromosomes, and thus genes do occur in pairs here.
- **Somatic Cells**: Somatic cells are also diploid (2n) and contain pairs of chromosomes, so genes do occur in pairs in somatic cells.
- **Endosperm Cells**: Endosperm cells are typically triploid (3n) in plants and also contain multiple sets of chromosomes, meaning genes occur in pairs as well.
- **Gametes**: Gametes are haploid (n), meaning they contain only one set of chromosomes. Therefore, genes do not occur in pairs in gametes.

4. **Conclusion**: Based on the analysis, the correct answer is that genes do not occur in pairs in **gametes**.

**Final Answer**: Gametes

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