Which one of the following conditions of the zygotic cell would lead to the birth of a normal human female…

Which one of the following conditions of the zygotic cell would lead to the birth of a normal human female child?
  1. Two X-chromosomes
  2. Only one Y-chromosome
  3. Only one X-chromosome
  4. One X and one Y-chromosome

Solution

The sex determining mechanism in case of humans is XY type. Sperms are of two types, one containing X-chromosome and another containing Y-chromosome. The ovum is of one type only, ie, contain X chromosome. The fertilization of ovum with Y-chromosome carrying sperm results into a male offspring.

Asked in: NEET 2011 (Mains)

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