Question

12 answer the following questions about pedigrees. (a) 1. ii. iii. part a which of the following correctly describes the parents in the first generation (i) of pedigree b? a they may or may not have the disorder b they are carriers for the disorder c they have no genes for this disorder d they are affected by the disorder

Explanation:

In pedigree analysis, the key is to interpret the symbols. The first - generation parents in Pedigree B are represented by a square (male) and a circle (female) with no shading. According to the key, unshaded symbols represent normal individuals. But since they have affected offspring (in generation II), they must be carriers. Carriers are individuals who have one copy of the recessive allele for a disorder (but do not show the disorder phenotype as they have a dominant normal allele as well).

Answer:

B. They are carriers for the disorder