Which Statement or Factor Is a Criterion for Autosomal-Recessive Transmission

Multiple Choice

Which statement or factor is a criterion for autosomal-recessive transmission of single-gene traits?

A) About 25% of the members of a large kindred with an autosomal-recessive trait will express the trait.
B) There is no carrier status; if the allele for the trait is present, it is expressed, although the degree of expression can be variable.
C) Individuals who are heterozygous for an autosomal-recessive trait have minimal risk for transmitting the allele to their offspring.
D) The degree of expression of an autosomal-recessive trait or disorder in a homozygous individual is directly related to the penetrance of the trait.