Q106 / 120 · NEET 2011 (Mains) · Zoology

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

  • Correct answer
    A
    Two X-chromosomes
  • B
    Only one Y-chromosome
  • C
    Only one X-chromosome
  • D
    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.

Hence, the correct answer is option: 'A'.

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