Pick ONE of the problems below and complete it. Question #…
Pick ONE of the problems below and complete it. Question #1. Blood types in humans are caused by a combination of two of three possible alleles – IA, IB, and i. The i allele is recessive and individuals homozygous for this allele have blood types O. Blood type A may be due to either homozygous condition or the IA i genotype. Blood type AB is caused by having a copy of both the IA and IB alleles. Rh factor is another “marker” on human red blood cells and is either positive (dominant—R) or negative (recessive—r). A man with blood type B-negative, whose father was A-positive and whose mother was AB-positive, married a woman that was B-positive. The woman’s mother was AB-negative and her father was AB-positive. Give the genotypes and phenotypes of the possible offspring from this marriage. Question #2. Normal vision (XA) in humans is dominant to color blindness (Xa) and is X-linked. The determiner for brown eyes (B) is dominant to blue eyes (b) and is not X-linked. A colorblind man with brown eyes, whose mother was blue-eyed, marries a brown-eyed woman having normal vision, whose father was colorblind with blue eyes. What is the expected phenotypic ratio of their male and female children involving eye color and color blindness.
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