Question

a parent cell has 5 homologous pairs of chromosomes. during meiosis i a non-disjunction event involving one chromosome occurs. what is the resulting number of chromosomes in each of the 4 gametes produced at the end of meiosis?

Answer 1

If nondisjunction occurs during meiosis I in a cell with 5 homologous pairs of chromosomes, two gametes would have 6 chromosomes (n + 1) and two would have 4 chromosomes (n - 1).

Step-by-step explanation:

If a parent cell has 5 homologous pairs of chromosomes and a nondisjunction event occurs during meiosis I involving one chromosome, this would lead to an abnormal distribution of chromosomes in the resulting gametes.

Specifically, nondisjunction in meiosis I means that the homologous chromosomes fail to separate properly.

As a result, two of the gametes would have an extra chromosome (n + 1), and two gametes would be missing a chromosome (n - 1).

Since the original cell had 5 pairs (10 chromosomes), the normal haploid number (n) should be 5.

Therefore, in this scenario, two of the gametes would end up with 6 chromosomes, and the other two would have only 4 chromosomes.