The following questions refer to the pedigree chart in Figure 14.2 for a family, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle.

Figure 14.2
-What is the likelihood that the progeny of IV-3 and IV-4 will have the trait?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Question

The following questions refer to the pedigree chart in Figure 14.2 for a family, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle.
  
Figure 14.2
-What is the likelihood that the progeny of IV-3 and IV-4 will have the trait?
A) 0% 
B) 25% 
C) 50% 
D) 75% 
E) 100%

Quizplus · Accepted Answer

The likelihood depends on the genetic makeup of IV-3 and IV-4. If the trait is autosomal recessive and both parents are carriers, there is a 50% chance their child will inherit one recessive allele from each parent, thus expressing the trait.

The Following Questions Refer to the Pedigree Chart in Figure