The yolk plug of gastrula represents in the later stage its

Options

A. Anterior end
B. Posterior end
C. Dorsal side
D. Ventral side

Explanation

**Step-by-Step Solution:**

1. **Understanding the Yolk Plug**: The yolk plug is a structure that forms during the gastrulation stage of embryonic development. It is primarily composed of yolk-filled cells.

2. **Location of the Yolk Plug**: The yolk plug is located at the vegetal pole of the embryo. This is the part of the embryo that contains a higher concentration of yolk, which provides nutrients for the developing embryo.

3. **Duration of the Yolk Plug**: The yolk plug is present for a relatively short period during development. It is an important structure during the early stages of gastrulation but does not persist throughout the entire development.

4. **Formation of the Yolk Plug**: The yolk plug fills the space between the dorsal and ventral lips of the blastopore. The blastopore is the opening that forms during gastrulation, leading to the development of the digestive tract.

5. **Identifying the Role of the Yolk Plug**: In later stages of development, the yolk plug contributes to the formation of the posterior end of the embryo. Therefore, the yolk plug is associated with the posterior side of the embryo.

6. **Conclusion**: Based on the above points, the yolk plug of the gastrula represents the posterior end in its later stages.

**Final Answer**: The yolk plug of the gastrula represents the posterior end in the later stage.

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