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 answerATwo X-chromosomes
- BOnly one Y-chromosome
- COnly one X-chromosome
- DOne 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'.