Which of these sets of cells divide slowly

Options

A. Micromeres
B. Megameres
C. Blastomeres
D. Mesomeres

Explanation

**Step-by-Step Solution:**

1. **Understanding the Cell Types**: The question asks which set of cells divides slowly. We need to analyze the different types of cells mentioned: micromeres, megameres, blastomeres, and mesomeres.

2. **Defining Blastomeres**: Blastomeres are the cells formed from the cleavage of the zygote. They are not characterized as slowly dividing cells. Therefore, this option is incorrect.

3. **Analyzing Micromeres and Megameres**:
- **Micromeres**: These are smaller cells located at the animal pole and are known for their relatively faster division.
- **Megameres**: These are larger cells located at the vegetal pole. Due to their larger size, they divide more slowly compared to micromeres.

4. **Understanding Mesomeres**: Mesomeres are cells that are of intermediate size, formed during cleavage. They are also not characterized as slowly dividing cells.

5. **Conclusion**: After analyzing all the options, the cells that divide slowly are the **megameres**.

**Final Answer**: Megameres

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