Which of the following reasons accounts for the fact that dominant alleles that cause lethal disorders are les

Question

Which of the following reasons accounts for the fact that dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders?
A) Unlike lethal disorders caused by recessive alleles, lethal disorders caused by dominant alleles usually cause death of the embryo.
B) Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce, whereas individuals carrying a lethal recessive allele are more likely to be healthy and reproduce.
C) Many lethal recessive alleles cause enhanced disease resistance when they are present in the heterozygous state, and carriers of these alleles have more children, on average, than other people.
D) The presence of a lethal dominant allele causes sterility.
E) Lethal disorders caused by dominant alleles are usually more severe than lethal disorders caused by recessive alleles.

Answer 1

B

Answer 2

Most true answer is c. reject a) due to the word 'usually' b) is occassionally true, but not common d) not always e) not always