Question

Which part of an egg contains the blastodisk?

• A. Egg white (Albumen)
• B. Egg shell
• C. Egg yolk
• D. Chalaza

Hint:

Blastodisk → Present on yolk → Site of embryo development.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks to identify the location of the blastodisk within the structure of a bird's egg. The blastodisk is crucial for embryonic development.
Step 2: Key Components of an Egg:
- Egg Yolk: The yellow, central part of the egg. It is rich in fats, vitamins, and minerals and serves as the primary food source for the developing embryo.
- Blastodisk (or Germinal Disc): A small, circular, whitish spot on the surface of the yolk. This area contains the genetic material from the hen. If the egg is fertilized, this spot is called a blastoderm and is where the embryo begins to develop.
- Egg White (Albumen): The clear liquid that surrounds the yolk. It is primarily composed of protein (albumin) and water, providing protection and additional nutrition for the embryo.
- Egg Shell: The hard, protective outer layer of the egg.
- Chalaza: Two rope-like structures that anchor the yolk in the center of the albumen.
Step 3: Detailed Explanation:
- The blastodisk is fundamentally part of the yolk's structure, appearing as a distinct spot on its surface.
- It is not located in the egg white, shell, or the chalaza. The chalaza merely holds the yolk in place.
Step 4: Final Answer:
The blastodisk is located on the egg yolk.