Question

Please answer??????
This pedigree chart tracks the inheritance of a recessive trait that is not sex-linked. Based on the information in the chart, which of the following statements is true?

Answer 1

A. Individual #8 must be heterozygous for the trait.

B. Individual #10 must be heterozygous for the trait.

C. Individual #13 must be homozygous dominant.

D. Individual #3 must be homozygous dominant

Answer 2

A is the correct answer. This is because #1 is homozygous recessive and #2 is heterozygous or homozygous dominant, hence at least hinting that #8 could be heterozygous. What confirms is the children of #8. For any children of #8 and 9 to be homozygous recessive and be affected by the disease, both should carry at least one recessive allele. Hence, #8 has a recessive allele and the fact that it is not affected proves that it is because of the dominant allele in it. Hence, heterozygous.