Which situation allows for evolution during gene duplication? a. existing genes are copied over generations. b. the original gene performs the same role as the mutated gene. c. the original gene never duplicates. d. a mutation occurs in one copy of the original gene.

In familial hypercholesterolemia individuals homozygous for the allele causing the disorder completely lack receptors on liver cells that take up cholesterol from the blood stream. heterozygous have one-half the number of receptors while individuals homozygous for the normal allele are phenotypically normal. this is an example of a.epistasis b.complete dominance c. incomplete dominance d. codominance

Consider the equation s + o2 ? so2. what is the product? question 3 options: s so 2 s + so 2 o 2

How do the sperm cells get from the stigma to the ovules? a. they slide down the petals to the bottom of the flower. b. they travel through pollen tubes. c. they travel along filaments. d. insects carry the sperm cells from the stigma to the ovules.