Ireally need with biologyin phenylketonuria (pku), an enzyme that converts one amino acid into another does not work properly. which of the following is the most likely cause of this genetic condition? a an error in the transcription of the gene for the enzymeb a mutation in the dna sequence that codes for the enzymec an excess of the amino acids necessary to produce the enzymed a structural variation in the amino acid modified by the enzyme  which of the following term(s) applies to traits, such as human eye color, that are controlled by more than one gene?   *a codominantb polygenicc recessived sex-linkedsome areas of a forest contain rich soil, while in other areas the soil is poor. plants of a certain species grow taller in the rich soil than in the poor soil. the taller plants receive more sunlight and are able to produce more offspring than the shorter plants. if these offspring grow in rich soil, they are tall, but if they grow in poor soil, they are short. which of the following statements best explains why this situation is not an example of evolution by natural selection?   *a the observed differences in plant height are not due to genetics. b the differences in soil conditions do not affect all plants equally. c the short plants and tall plants are not isolated enough from each other. d the short plants are not accumulating gene mutations as quickly as the tall plants. female cattle that have white coats are crossed with male cattle that have red coats. both male and female offspring have roan coats, which are coats with both red hairs and white hairs. which of the following best describes the genetics of coat color in the cattle?   *a the red and white alleles are sex-linked. b the red and white alleles are codominant. c the red allele is recessive to the white allele. d the red allele is dominant to the white allele. a single nucleotide of dna is composed of whichof the following substances?   *a adenine, guanine, and cytosineb hydrogen, a phosphate group, and adeninec ribose sugar, deoxyribose sugar, and thymined deoxyribose sugar, a phosphate group, and a nitrogenous base