Which genetic disorders, caused by an extra x chromosome (xxy), is characterized by a lack of testicular development in males, effeminate features, possible mental impairment, and a thin stature? a) down's syndrome b) turner syndrome c) sickle cell anemia d) klinefelter's syndrome

D

Explanation:

This is caused mainly by nondisjunction of the sex chromosomes in gametes during meiosis. Therefore a gamete will have both XX chromosomes and fuse with a normal one with Y during fertilization. An XY gamete can also fuse with a normal one with X chromosome. These males with Klinefelter's syndrome produce less than normal levels of testosterone.

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.