Assertion : Down's syndrome, Klinefelter's syndrome and Turner's syndrome are chromosomal disorders. Reason : In Klinefelter's syndrome, females are sterile.

Step-by-step solution

Klinefelter's syndrome is a genetic condition that only affects males. The condition is present from birth and is due to an extra X chromosome. Normal males have 45+X Y chromosomes but males with Klinefelter's syndrome have 45+ XXY chromosome. This condition arises due to non-disjunction at the time of gamete formation leading to formation of abnormal gamete. When either a normal egg fuses with abnormal sperms (XY) or an abnormal egg (XX) fuses with a normal sperm it results in an abnormal zygote, which develops in