Neet Solved Paper 2015 Question 75
Question: An abnormal human baby with XXX sex chromosomes was born due to
Options:
A) formation of abnormal sperms in the father
B) formation of abnormal ova in the mother
C) fusion of two ova and one sperm
D) fusion of two sperms and one ovum
Show Answer
Answer:
Correct Answer: B
Solution:
- Formation of an abnormal ova usually occurs as an event during the formation of reproductive cells. An error in cell division called non-disjunction can result in reproductive cells with additional chromosomes. Any of these cells if contributes in the genetic makeup of child leads to trisomy of X-chromosome i.e. the child will have an extra X-chromosome. ZZ + XX in mother will lead to birth of a XXX genotype baby.
