Question

The incident of autism has increased in the past couple of decades. Scientists have found the answer to that which in part is due to the fact that men are fathering children at later ages than previously. How does this provide an explanation for the increase in rate of autism? This question has more than one correct answer.

A. Somatic cells accumulate more mutations at older age

B. Autism is an X-linked disorder and males have only one X chromosome

C. Meiosis will experience more nondisjunction at later age in males than females

D. DNA replication error increases by age

E. Older male's germ cells have more mutations

Answer 1

Sperm divide more often than egg cells do . With each division, a cells's DNA is copied which presents an opportunity for a mutation to occur. So more the age, the more division the sperm cell has undergone and increases the probability of accumulating mutations in DNA which increases the risk of autism . Also it takes more number of mutations to trigger autism in females as compared to males because of the fact that males have only one X chromosome.

Hence the best option to answer this question will be B,D and E.