AP BIOLOGY

HEREDITY

SEX INFL UENCED INHERITANCE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
If a trait shows up more commonly in men than women it is probably
A
not inherited
B
on the x chromosome and dominant
C
on the x chromosome and recessive
D
on a normal body chromosome
Explanation: 

Detailed explanation-1: -Recessive X-linked traits appear more often in males than females because, if a male receives a “bad” allele from his mother, he has no chance of getting a “good” allele from his father (who provides a Y) to hide the bad one.

Detailed explanation-2: -X-linked recessive diseases most often occur in males. Males have only one X chromosome. A single recessive gene on that X chromosome will cause the disease.

Detailed explanation-3: -Fathers cannot pass X-linked recessive conditions to their sons. When a son inherits a mutated gene on the X chromosome from his mother, the genetic condition is more likely to occur. X-linked recessive conditions most often occur in males.

Detailed explanation-4: -X-linked recessive inheritance refers to genetic conditions associated with mutations in genes on the X chromosome. A male carrying such a mutation will be affected, because he carries only one X chromosome. A female carrying a mutation in one gene, with a normal gene on the other X chromosome, is generally unaffected.

Detailed explanation-5: -X-linked dominant disorders are seen more commonly in females than in males, or in the case of some diseases, affect only females. In the latter case, it is thought that the hemizygous males are so severely affected, they do not survive.

There is 1 question to complete.