Exam 4: Patterns of Inheritance

When calculating the recurrence risk for a complex, possibly polygenic disorder with a couple who already have one child with the disorder, which additional factorhasthe greatest impact on increasing this risk?

Which situation most closely represents an example of "regression to the mean"?

Which statement reflects the criterion for autosomal-dominant transmission of single-gene traits?

What is the risk for a person to inherit an autosomal-dominant genetic disease-causing allele from a parent who is heterozygous if the disorder has a penetrance factorof 75%?

Why are dizygotic twins less likely to show concordance for a monogenic trait than monozygotic twins?

An infant with type B blood is born to parents who both have type O blood. What genetic action or phenomenon is responsible for this unusual blood type expression?

A woman (Adele) has three daughters (Barbara, Brenda, Beverly) with a man (Adam) who is color-blind. Barbara has a daughter (Carol) and a son (Cliff) who havenormal color vision. Brenda has no children. Beverly has two sons (Carl, Charlie) who are both color-blind. To which genetic generation do Carl and Charlie belong?

Which statement is a criterion for an autosomal-dominant pattern of inheritance of a specific trait or characteristic that is highly penetrant?

Which genetic disorder has both an autosomal-dominant and an autosomal-recessive form?

With which type of inheritance pattern does the trait or disorder usually first appear among siblings rather than in parents of affected children?

Which trait or disorder has both an autosomal-dominant form and an autosomal-recessive form?

Which statement regarding inheritance of an autosomal-dominant gene allele with known variability in expressivity is true?

Which statement or condition best reflects multifactorial inheritance?

Is it possible for two parents with achondroplasia to have a child who is of normal stature?

Mating of a female rabbit with a long tongue with a male rabbit that had a short tongue resulted in 12 offspring. Two had long tongues, two had short tongues,and eight had medium-length tongues. Which allele combinations explains the tongue lengths of the offspring?

Which common health problem has the highest heritability estimate?

If a man with classic hemophilia (X-linked recessive) has children with a woman who is a carrier for the disorder, what is the expected risk pattern?

Which situation is an example of modifier gene action?

What is the most likely explanation for the expression of responses related to pleiotropy?

What is the significance of a shift to the left in the threshold value of liability in a threshold of liability model for the expression of a complex health problemwith genetic influences?