Which one of the following statements is correct regarding cleavage?

Options

A. Cleavage division brings about a considerable increase in the mass of protoplasm.
B. It is a type of meiotic division
C. With each cleavage division, the resultant blastomeres increases in size.
D. Cleavage division in morula leads to the development of blastula.

Answer

To solve the question regarding which statement is correct about cleavage, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Understanding Cleavage**:
- Cleavage is the process of rapid cell division that occurs after fertilization. It involves mitotic divisions of the zygote, leading to an increase in the number of cells (blastomeres) without an increase in overall mass.

2. **Analyzing the Statements**:
- **Statement 1**: "Cleavage division brings about a considerable increase in the mass of protoplasm."
- This statement is incorrect. During cleavage, the number of cells increases, but the overall mass of protoplasm does not significantly increase because the cells do not grow in size during this process.

- **Statement 2**: "It is a type of meiotic division."
- This statement is also incorrect. Cleavage involves mitotic divisions, not meiotic divisions. Meiosis is a reductional division, which does not occur in the zygote during cleavage.

- **Statement 3**: "With each cleavage division, the resultant blastomeres increase in size."
- This statement is incorrect. In fact, with each cleavage division, the size of the individual cells (blastomeres) decreases because the total volume of the zygote is divided among more cells.

- **Statement 4**: "Cleavage division in morula leads to the development of blastula."
- This statement is correct. The morula is an early stage of development consisting of 8 to 16 cells, and as cleavage continues, it leads to the formation of the blastula, which has approximately 100 cells.

3. **Conclusion**:
- The correct statement regarding cleavage is: "Cleavage division in morula leads to the development of blastula." Therefore, the answer is option D.