Question

If an individual has trisomy resulting in Down syndrome and has an extra chromosome in each cell, what mutation must have occurred?
A. A nondisjunction mutation in the gamete of one of the parents
B. A nondisjunction in both gametes of the parents
C. A nondisjunction in one of the first gamete cells of the individual
D. A nondisjunction mutation in body cells of both parents

Answer 1

Answer:

if  An individual has an extra chromosome in every one of its cells, the mutation that must have occurred is A non-disjunction mutation in the gamete of one of the parents