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NEET2005ZoologyHuman ReproductionActual

Grey crescent is the area:

Options

  1. Aat the point of entry of sperm into ovum
  2. Bjust opposite to the site of entry of sperm into ovum
  3. Cat the animal pole
  4. Dat the vegetal pole.

Correct answer

B. just opposite to the site of entry of sperm into ovum

Step-by-step solution

Grey crescent marks the future dorsal side of the embryo. Subsequently, it was determined that the Grey Crescent is formed by the 30^ rotation of the fertilized egg to form a dorsal/ ventral axis. The crescent thus serves as a determinant of dorsal / ventral polarity: cells without it have no means of orientation. Related Theory In the zygote of the frog, there are two poles present. The vegetal pole and the animal pole. These are separated by an area which is rich in melanin and is known as the grey crescent. The

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