During cleavage. What is true about cells?

Options

A. Nucleocytoplasmic ratio remains unchanged
B. Size does n ot increase
C. There is less consumption of oxygen
D. The division is like me iosis.

Answer

### Step-by-Step Solution:

1. **Understanding Cleavage**: Cleavage is the series of rapid cell divisions that occur after fertilization. It leads to the formation of a multicellular structure called a blastula.

2. **Cell Division Characteristics**: During cleavage, the primary characteristic is that the cells divide rapidly without significant growth in size. This means that the overall volume of the embryo does not increase significantly during these early divisions.

3. **Nuclear-Cytoplasmic Ratio**: The nuclear-cytoplasmic ratio remains relatively unchanged during cleavage. This means that while the number of cells increases, the amount of cytoplasm per cell does not increase significantly.

4. **Oxygen Consumption**: Contrary to the statement in the options, there is actually an increase in metabolic activity and oxygen consumption during cleavage as the cells are rapidly dividing.

5. **Type of Cell Division**: The type of division that occurs during cleavage is not like meiosis. Instead, it is similar to mitosis, where the cells divide to produce two identical daughter cells.

6. **Conclusion**: Based on the characteristics of cleavage, the correct statement about cells during this phase is that their size does not increase significantly.

### Final Answer:
The correct answer is **b, size does not increase**.

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