Use the following pedigree (Figure 14.3) for a family in which dark-shaded symbols represent individuals with one of the two major types of colon cancer. Numbers under the symbols are the individual's age at the time of diagnosis.

Figure 14.3
-What is the genotype of the deceased individual in generation II?

Question

Use the following pedigree (Figure 14.3) for a family in which dark-shaded symbols represent individuals with one of the two major types of colon cancer. Numbers under the symbols are the individual's age at the time of diagnosis.
  
Figure 14.3
-What is the genotype of the deceased individual in generation II?

Quizplus · Accepted Answer

Since the individual in question is affected by colon cancer, they must have at least one copy of the cancer allele. Since their unaffected sibling inherited the non-cancer allele from both parents, the deceased individual must have inherited one cancer allele from one parent and one non-cancer allele from the other parent, making them heterozygous for the gene for colon cancer.

Use the Following Pedigree (Figure 14