Author Question: Parents ask the nurse about the characteristics of autosomal dominant inheritance. Which statement ... (Read 90 times)

Melani1276 · **on:** Jun 28, 2018

Parents ask the nurse about the characteristics of autosomal dominant inheritance. Which statement is characteristic of autosomal dominant inheritance?

a. Females are affected with greater frequency than males.
b. Unaffected children of affected individuals will have affected children.
c. Each child of a heterozygous affected parent has a 50 chance of being affected.
d. Any child of two unaffected heterozygous parents has a 25 chance of being affected.

Question 2

Which is a sex chromosome abnormality that is caused by the presence of one or more additional X chromosomes in a male?

a. Turner
b. Triple X
c. Klinefelter
d. Trisomy 13

soda0602 · **Reply #1 on:** Jun 28, 2018

Answer to Question 1

ANS: C
In autosomal dominant inheritance, only one copy of the mutant gene is necessary to cause the disorder. When a parent is affected, there is a 50 chance that the chromosome with the gene for the disorder will be contributed to each pregnancy. Males and females are equally affected. The disorder does not skip a generation. If the child is not affected, then most likely he or she is not a carrier of the gene for the disorder. In autosomal recessive inheritance, any child of two unaffected heterozygous parents has a 25 chance of being affected.

Answer to Question 2

ANS: C
Klinefelter syndrome is characterized by one or more additional X chromosomes. These individuals are tall with male secondary sexual characteristics that may be deficient, and they may be learning disabled. An absence of an X chromosome results in Turner syndrome. Triple X and trisomy 13 are not abnormalities that involve one or more additional X chromosomes in a male (Klinefelter syndrome).