a Is this a dominant or recessive trait Explain why b What

a. Is this a dominant or recessive trait? ___ Explain why. b. What are the genotypes of I-1 and I-2? c. What was the probability the parental couple would have 3 unaffected and 1 affected offspring?

Solution

a. it is a dominant trait.

if we assume that the square box is a diseased male. we then observe that this an X-linked trait. approx half of the off springs are also diseased which implies that this is autosomal ( defect in non-sex chromosome) dominant in nature.

Both the affected males and females have equal probability of getting the disease and transmitting the trait to the next generation.Since the disease is dominant, it can be manifested in an individual even if only one defective allele is inherited.