Cell division in zygote is called-
(a) Cleavage
(b) Segmentation
(c) Cellulation
(d) All the above

Options

A. Cleavage
B. Segmentation
C. Cellulation
D. All the above

Answer

To solve the question "Cell division in zygote is called-", we need to analyze the options provided and understand the process of cell division in the zygote.

### Step-by-Step Solution:

1. **Understanding Zygote Formation**:
- A zygote is formed when an egg and sperm fuse during fertilization. This results in a diploid structure.

2. **Cell Division in Zygote**:
- After the formation of the zygote, it undergoes a series of cell divisions. This process is crucial for the development of the embryo.

3. **Type of Cell Division**:
- The specific type of cell division that occurs in the zygote is known as cleavage. Cleavage is characterized by rapid cell division without significant growth, resulting in smaller cells called blastomeres.

4. **Other Names for Cleavage**:
- Cleavage is also referred to as segmentation and cellulation. These terms describe the same process of division occurring in the zygote.

5. **Analyzing the Options**:
- (a) Cleavage: Correct, as this is the primary term used for cell division in the zygote.
- (b) Segmentation: Also correct, as it is another name for cleavage.
- (c) Cellulation: Correct as well, since it refers to the same process.
- (d) All the above: This option is correct because all the terms mentioned (cleavage, segmentation, and cellulation) refer to the same process of cell division in the zygote.

6. **Conclusion**:
- Therefore, the correct answer is (d) All the above.