Answer to Question 1
B
Multifactorial disorders result from an interaction between a person's genetic susceptibility and environmental conditions that favor development of the defect. They are characteristi-cally present and detectable at birth.
They are usually detectable at birth.
They are usually single isolated defects, although the primary defect may cause secondary defects.
Secondary defects can occur with multifactorial disorders.
Answer to Question 2
A
Types A and B are equally dominant, and the baby can thus inherit one from each parent.
The infant has inherited both blood types from the parents; it is not a mutation.
Both types A and B are equally dominant.
Both types A and B are dominant.