Question Detail
Question
In the case of frog, the structure known as 'grey crescent' is found in
Correct Answer
Option A is the correct answer.
Detailed Explanation
The grey crescent is a structure that appears in the fertilized egg of amphibians (such as frogs) shortly after fertilization. It forms opposite the point of sperm entry and marks the dorsal side of the embryo. It is a key landmark for embryonic polarity and is involved in the organization of the body plan. It is not present in unfertilized eggs.
Hint
This structure appears only after fertilization and is important for establishing the dorsal-ventral axis.