Alissa is a 41-year-old, married, professional woman who has just found out that she is pregnant with her third child. According to your textbook, which of the following conditions is her baby at higher risk of due to Alissa's age? a) Down syndromeb) Phenylketonuriac) ADHDd) Von Recklinghausen disease (neurofibromatosis)

Down syndrome.

Explanation:

Down syndrome may be defined as the medical condition that occurs due to the presence of extra chromosome at the chromosome number 21. The individual has big head, rolled finger and tongue.

The chances of Down syndrome increases as the mother's age increases. The egg of the female get arrested at diplotene stage and with the increased age of mother the phenomena like translocation and non disjunction increases at this stage.

Thus, the correct answer is option (a).