Embryo at 16-32 cell stage is called

Options

A. Blastula
B. Morula
C. Trophoblast
D. Inner cell mass

Answer

To determine what an embryo at the 16-32 cell stage is called, we can follow these steps:

### Step 1: Understand the Stages of Embryonic Development
- After fertilization, the zygote undergoes a series of cell divisions known as cleavage. This process leads to the formation of multiple cell stages.

### Step 2: Identify the Relevant Cell Stages
- The cleavage divisions progress through several stages:
- 2-cell stage
- 4-cell stage
- 8-cell stage
- 16-cell stage
- 32-cell stage

### Step 3: Define the Terms
- **Plastula**: This term typically refers to the earliest phase of embryonic development, which is not specific to the 16-32 cell stage.
- **Morula**: This term refers to a solid mass of cells formed after the cleavage divisions, specifically at the 16-cell stage and can extend to the 32-cell stage.
- **Trophoblast**: This is the outer layer of cells in the blastocyst, which forms after the morula stage.
- **Inner Cell Mass**: This refers to the group of cells within the blastocyst that will eventually develop into the embryo proper.

### Step 4: Conclusion
- Based on the definitions and the stages of development, the correct term for the embryo at the 16-32 cell stage is **morula**.

### Final Answer
The embryo at the 16-32 cell stage is called **morula**.

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