Question

what occurs when there is one normal x chromosome and the other sex chromosome is missing or altered?
a trisomy 18
b trisomy 21
c klinefelter syndrome
d turner’s syndrome

Explanation:

Turner's syndrome is a condition where a female is born with one normal X - chromosome and the other sex chromosome (either X or Y) is missing or altered. Trisomy 18 and 21 involve extra copies of autosomes (chromosome 18 and 21 respectively). Klinefelter syndrome is when a male has an extra X - chromosome (XXY).

Answer:

D. Turner's syndrome