Question

marfan syndrome is an autosomal genetic disorder that affects connective tissue in the body. the pedigree chart of a particular family with marfan syndrome is shown below. which of the following identifies the most likely type of inheritance for marfan syndrome, the genotype of individual iii - 2, and the phenotype of individual ii - 8? type of inheritance genotype of iii - 2 phenotype of ii - 8 recessive affected mm type of inheritance genotype of iii - 2 phenotype of ii - 8 dominant unaffected mm type of inheritance genotype of iii - 2 phenotype of ii - 8 recessive mm affected type of inheritance genotype of iii - 2 phenotye of ii - 8 dominant mm unaffected

Explanation:

Step1: Analyze inheritance type

In the pedigree, the trait appears in every generation, which is a characteristic of dominant inheritance. Recessive inheritance would often skip generations.

Step2: Determine genotype of III - 2

Since Marfan syndrome is dominant, and III - 2 is not affected, the genotype must be homozygous recessive, which is $mm$.

Step3: Determine phenotype of II - 8

II - 8 is not shaded (not affected), so the phenotype is unaffected.

Answer:

D. Type of inheritance: Dominant, Genotype of III - 2: $mm$, Phenotype of II - 8: Unaffected