Morula is a development stage:

Options

A. between the zygote and blastocyst
B. between the blastocyst and gastrula
C. after the impantation
D. between implantation and parturition

Explanation

**Step-by-Step Solution:**

1. **Understanding Fertilization:**
- Fertilization is the process where the male gamete (sperm) fuses with the female gamete (egg) to form a zygote.

2. **Formation of Zygote:**
- After fertilization, a single cell called the zygote is formed.

3. **Mitotic Division:**
- The zygote undergoes a series of mitotic divisions. This means that the zygote divides to produce more cells.

4. **Cleavage of Zygote:**
- During these mitotic divisions, the zygote undergoes cleavage, which is the process of cell division that leads to the formation of multiple smaller cells from the zygote.

5. **Formation of Blastomeres:**
- As the zygote divides, it produces a series of cells called blastomeres. Initially, the zygote divides into two blastomeres, then those two divide into four, and this process continues.

6. **Morula Stage:**
- The morula is specifically defined as the stage when the zygote has divided into a solid ball of 16 to 32 blastomeres. This stage resembles a mulberry, which is where the name "morula" comes from.

7. **Conclusion:**
- Therefore, the morula is a developmental stage that occurs after the zygote has undergone several rounds of mitotic divisions, resulting in a cluster of cells.

---