Question

Which of the following human genetic conditions is missing a chromosome?

A) Turner syndrome
B) Down's syndrome
C) Jacob syndrome
D) Klinefelter syndrome

Answer 1

Turner syndrome is the human genetic condition where a chromosome is missing, specifically it is characterized by having only one X chromosome without the accompanying X or Y chromosome.

Step-by-step explanation:

The human genetic condition that is characterized by the absence of a chromosome is Turner syndrome. Individuals with Turner syndrome have a single X chromosome instead of the typical two sex chromosomes, making their genotype X instead of XX or XY. This genetic condition leads to a variety of developmental issues, including sterility, as the sexual organs do not mature properly. In contrast, conditions such as Down's syndrome, Klinefelter syndrome, and Jacob syndrome are caused by the presence of an extra chromosome. Down's syndrome (trisomy 21) involves an extra chromosome 21, Klinefelter syndrome is characterized by an XXY genotype, and Jacob syndrome by an XYY genotype.