At which stage, the implantation in uterus takes place?

Options

A. 8-cell stage
B. Morula
C. Blastocyst
D. Late gastrula

Answer

**Step-by-Step Solution:**

1. **Understanding the Stages of Embryonic Development:**
- After fertilization, the zygote undergoes a series of mitotic divisions. These divisions lead to the formation of multiple stages: the 2-cell stage, 4-cell stage, 8-cell stage, and finally the Morula stage.

2. **Identifying the Morula Stage:**
- The Morula is a solid ball of cells formed after several divisions of the zygote. It typically consists of about 8 to 16 cells, known as blastomeres.

3. **Transition to the Blastocyst Stage:**
- Following the Morula stage, further cell division and differentiation occur, leading to the formation of the Blastocyst. The Blastocyst has a hollow structure with an inner cell mass and an outer layer called the trophoblast.

4. **Implantation Process:**
- The Blastocyst travels to the uterus, where it will implant into the endometrium (the inner lining of the uterus). This process of embedding the Blastocyst into the uterine wall is known as implantation.

5. **Conclusion:**
- Therefore, the implantation in the uterus takes place at the Blastocyst stage.

**Final Answer:**
- The implantation in the uterus takes place at the Blastocyst stage.

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