Considering that males can have Klinefelter (XXY) syndrome, XYY, and normal XY chromosomal combinations, and females can have Turner (XO) syndrome, poly-X (XXX, XXXX), and normal XX combinations, it is obvious that
A) male characteristics result from the presence of only one X chromosome.
B) male characteristics result from the absence of two or more X chromosomes.
C) male characteristics result from the minimal presence of one Y chromosome.
D) female characteristics result from the presence of two or more X chromosomes.
E) sex determination is a delicate balance between X and Y chromosomes.

Question

Considering that males can have Klinefelter (XXY) syndrome, XYY, and normal XY chromosomal combinations, and females can have Turner (XO) syndrome, poly-X (XXX, XXXX), and normal XX combinations, it is obvious that
A) male characteristics result from the presence of only one X chromosome.
B) male characteristics result from the absence of two or more X chromosomes.
C) male characteristics result from the minimal presence of one Y chromosome.
D) female characteristics result from the presence of two or more X chromosomes.
E) sex determination is a delicate balance between X and Y chromosomes.

Quizplus · Accepted Answer

Male characteristics result from the presence of the minimal amount of one Y chromosome. The Y chromosome contains the key gene SRY, which triggers the development of male gonads (testes) in the early stages of embryonic development. The X chromosome does not determine maleness, but rather contributes to other traits such as height, hair color, and immune function. Therefore, males can have a variety of chromosomal combinations as long as they have at least one Y chromosome to trigger male development.

Considering That Males Can Have Klinefelter (XXY) Syndrome, XYY, and Normal