In klinefelter syndrome, individuals are phenotypically male, but have reduced sperm production and may have some breast development in adolescence. the cells of klinefelter individuals have two x chromosomes and one y (they are xxy instead of xy).
this occurs because of what meiotic error?
a. aneuploidy
b. polyploidy
c. translocation
d. monosomy
e. duplication

Aneuploidy.

Explanation:

Aneuploidy may be defined as the condition in which the individual has either a extra chromosome or missing chromosomes but not the pair of the chromosome. Thigh might occur due to mutation or segregation error.

Klinefelter syndrome is the condition in which the individual male has extra X chromosome and shows XXY. The extra one X chromosome shows the case of trisomy and considered under the aneuploidy condition because a single chromosome is extra.

Thus, the correct answer is option (a).