In Addition to Interactions Among Genes, and Between Genotype and Environmental

Multiple Choice

In addition to interactions among genes, and between genotype and environmental influences, another crucial factor in the relationship between genotype and phenotype is:

A) the fact that gene expression is inflexible and unresponsive to internal factors.
B) that genes can mutate or spontaneously change from one generation to the next.
C) that because of the blood-brain barrier, teratogens such as exposure to radiation or chemical toxins do not affect the genotype or damage DNA.
D) the fact that the vast majority of genes in the human genome are never expressed.