Question

An abnormal human baby with ‘sex chromosomes XXX’ was born due to:
A. Fusion of two ova and one sperm
B. Fusion of two sperms and one ovum
C. Formation of abnormal sperms in the father
D. Formation of abnormal ova in the mother

Answer 1

Hint: An abnormal baby with chromosomes- XXX is called a super female. It is a very rare genetic defect that occurs due to error in the gamete formation during meiosis 1 and 2.

Complete answer:
In mammals including human beings XY method of sex determination is followed. It is also called male heterogamety.
The females in such organisms are homomorphic having the XX chromosomes while the males are heteromorphic and possess the XY chromosomes. The Y chromosome is shorter than the X chromosome. So females form only one type of gametes (i.e. the gametes have only X chromosome) while the males form two types of gametes called angiosperms (22 + X) and gymnosperms (22 + Y). So only a mother can produce an abnormal gamete with XX chromosomes as the gamete produced by father can have only one X chromosome.
The defect occurs due to abnormal ova produced in the mother. The mother produces gametes with XX chromosome instead of X chromosome which when fuses with the sperm of the father with X chromosome produces an abnormal  baby with chromosomes- XXX.
There are no such symptoms of this disorder. However, the girls with such genotypes are generally taller than other average girls. Sometimes they may also have seizures, flat feet, widely spaced eyes, anxiety, depression, dyslexia, kidney abnormalities, ovary abnormalities, developmental delays and learning disabilities.

Note:  This is not an inherited genetic disorder but occurs due to some error during the gamete formation. The defect occurs in the 47th chromosome so it is also called 47, triple X syndrome.