What happens during gastrulation?

Explanation

**Step-by-Step Text Solution:**

1. **Introduction to Gastrulation**: Gastrulation is a crucial phase in embryonic development that occurs after the formation of a blastocyst, typically when the embryo has around 1000 cells.

2. **Implantation**: During gastrulation, the embryo implants itself into the uterine wall. This is an essential step for the embryo to receive nutrients and support for further development.

3. **Fate Determination**: After implantation, the next significant event is fate determination. This process involves deciding what type of cells will develop from the embryonic cells.

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