In vitro fertilisation is a technique that involves transfer of which one of the following into the fallopian tube?

Options

A. Zygote only
B. Embryo only, upto 8 cell stage
C. Either zygote or early embryo upto 8 cell stage
D. Embryo of 32 cell stage

Answer

**Step-by-Step Solution:**

1. **Understanding In Vitro Fertilization (IVF):**
- In vitro fertilization is a reproductive technology that involves fertilizing an egg with sperm outside the body, in a controlled environment.

2. **Fertilization Process:**
- During IVF, male and female gametes (sperm and egg) are combined in a laboratory setting to allow fertilization to occur. This results in the formation of a zygote.

3. **Development of the Zygote:**
- After fertilization, the zygote undergoes several rounds of mitotic divisions. It first divides into two cells, then four, then eight, and continues to divide further.

4. **Embryo Development:**
- The zygote develops into an embryo through these divisions. However, after the 8-cell stage, the cells begin to differentiate, which means they start to take on specific functions.

5. **Transfer into the Fallopian Tube:**
- For successful implantation and further development, the zygote or the early embryo (up to the 8-cell stage) needs to be transferred into the fallopian tube or uterus. This transfer is crucial as differentiation of cells begins after the 8-cell stage, and such processes are best supported within the mother's body.

6. **Identifying the Correct Answer:**
- The options provided include:
- Zygote only
- Embryo only up to 8 cell stage
- Either zygote or early embryo up to 8 cell stage
- Embryo of 32 cell stage
- The correct answer is "either zygote or early embryo up to 8 cell stage," as this is the stage suitable for transfer into the fallopian tube.

**Final Answer:**
- The correct option is: **Either zygote or early embryo up to 8 cell stage.**

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