Which parental pair could produce a color- blind female? (1) homozygous normal-vision mother and color-blind father (2) color-blind mother and normal-vision father (3) heterozy- gous normal-vision mother and normal-vision father (4) heterozygous normal-vision mother and color-blind father

To determine which parental pair could produce a color-blind female, we need to consider the inheritance pattern of color blindness. Color blindness is a sex-linked trait, meaning it is carried on the X chromosome.

In option (1), we have a homozygous normal-vision mother and a color-blind father. Since the mother is homozygous for normal vision, she can only pass on a normal X chromosome to her offspring. The father, being color-blind, can only pass on a color-blind X chromosome. Therefore, this parental pair cannot produce a color-blind female.

In option (2), we have a color-blind mother and a normal-vision father. Since the mother is color-blind, she can only pass on a color-blind X chromosome. The father, being normal-vision, can pass on either a normal or a color-blind X chromosome. Therefore, this parental pair could produce a color-blind female.

In option (3), we have a heterozygous normal-vision mother and a normal-vision father. The mother, being heterozygous, can pass on either a normal or a color-blind X chromosome. The father, being normal-vision, can only pass on a normal X chromosome. Therefore, this parental pair cannot produce a color-blind female.

In option (4), we have a heterozygous normal-vision mother and a color-blind father. The mother, being heterozygous, can pass on either a normal or a color-blind X chromosome. The father, being color-blind, can only pass on a color-blind X chromosome. Therefore, this parental pair could produce a color-blind female.

Based on this analysis, the parental pairs that could produce a color-blind female are option (2) - color-blind mother and normal-vision father, and option (4) - heterozygous normal-vision mother and color-blind father.