Cleavage differs from mitosis because

Options

A. In cleavage there is no growth phase
B. In cleavage consumption of `O_(2)` of increases
C. In cleavage nucleus-cytoplasmic ratio increases
D. All the above.

Answer

### Step-by-Step Solution:

1. **Understanding Cleavage and Mitosis**:
- Cleavage is a series of rapid cell divisions that occur in the early stages of embryonic development, specifically in animal cells. It involves the division of the cytoplasm.
- Mitosis is the process of nuclear division where one nucleus divides to form two identical nuclei, typically followed by cytokinesis, which divides the cytoplasm.

2. **Identifying Key Differences**:
- **Growth Phase**: In cleavage, there is no growth phase between divisions. The cells divide rapidly without increasing in size. In contrast, mitosis includes an interphase where the cell grows and DNA is replicated.
- **Oxygen Consumption**: Cleavage is characterized by a high rate of oxygen consumption due to the rapid cell divisions. In mitosis, the oxygen consumption is relatively low.
- **Nuclear-Cytoplasmic Ratio**: During cleavage, the nuclear-cytoplasmic ratio increases as the cytoplasm divides into smaller cells without a corresponding increase in the nucleus size. In mitosis, this ratio remains relatively constant as the cell grows and divides.

3. **Evaluating the Options**:
- **Option A**: "In cleavage there is no growth phase" - This is true.
- **Option B**: "In cleavage consumption of oxygen increases" - This is also true.
- **Option C**: "In cleavage nuclear cytoplasmic ratio increases" - This statement is true as well.
- **Option D**: "All of the above" - Since all the previous statements are true, this option is correct.

4. **Conclusion**:
- Therefore, the correct answer to the question "Cleavage differs from mitosis because" is **Option D: All of the above**.