Cleavage is found in

Options

A. Zygote
B. Eggs
C. Undivided cell
D. After gastrula stage

Answer

### Step-by-Step Solution:

1. **Understanding Cleavage**: Cleavage refers to the series of rapid cell divisions that occur after fertilization. This process does not involve cell growth; instead, it divides the zygote into smaller cells called blastomeres.

2. **Formation of Zygote**: After fertilization, the sperm and egg combine to form a zygote. This zygote is diploid, meaning it contains two sets of chromosomes.

3. **Initiation of Cleavage**: The zygote undergoes cleavage, which is characterized by rapid mitotic divisions. This process begins soon after fertilization.

4. **Development of Morula**: As cleavage continues, the zygote divides multiple times, eventually forming a solid ball of cells known as the morula. This stage typically consists of 16 cells.

5. **Transition to Blastula**: Following the morula stage, the cells begin to rearrange and form a hollow structure called the blastula. This stage is marked by the presence of a fluid-filled cavity known as the blastocoel.

6. **Gastrulation**: The blastula then undergoes a process called gastrulation, leading to the formation of the gastrula, which will eventually develop into the various tissues and organs of the organism.

7. **Conclusion**: Since cleavage is specifically the process that occurs in the zygote right after fertilization, the correct answer to the question "Cleavage is found in" is the zygote.

### Final Answer:
Cleavage is found in **Zygote**.

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