The _______ rolls down from the fallopian tube and attaches itself to the wall of the uterus.

Options

A. Embryo
B. Uterus
C. Fallopian tube
D. Foetus

Answer

**Step-by-Step Solution:**

1. **Understanding the Reproductive Process**: In the female reproductive system, the process begins with the ovary releasing an egg (ovum). This egg travels through the fallopian tube.

2. **Fertilization**: If sperm is present, fertilization occurs in the fallopian tube, forming a zygote. The zygote is a single cell that results from the fusion of the sperm and egg.

3. **Cell Division**: After fertilization, the zygote undergoes several rounds of cell division as it moves down the fallopian tube towards the uterus. This process transforms the zygote into a multicellular structure.

4. **Formation of the Embryo**: As the zygote divides, it forms a cluster of cells. When this cluster reaches about 10 to 15 cells, it is referred to as an embryo.

5. **Implantation in the Uterus**: The embryo continues to travel down the fallopian tube and eventually reaches the uterus. It then rolls down and attaches itself to the wall of the uterus, where it can implant and continue to develop.

6. **Conclusion**: Therefore, the correct answer to the question is "embryo," as it is the structure that rolls down from the fallopian tube and attaches itself to the wall of the uterus.

**Final Answer**: The **embryo** rolls down from the fallopian tube and attaches itself to the wall of the uterus.

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