Final answer:
The statement is false; both the genotype and environmental factors, such as sun exposure and temperature, significantly influence gene expression and the resulting phenotype, as demonstrated by scientific studies and Mendel's experiments.
Step-by-step explanation:
The statement, "The environment has little effect on the expression of the gene pair(s) controlling a qualitative trait" is False. Although the genotype that a cell possesses remains constant, the expression of genes is dependent on environmental conditions. This can be seen in traits such as skin color, which vary with sun exposure, and in species with temperature-dependent sex determination, where the environment influences the sex of the offspring. Furthermore, studies like Moree's on Drosophila melanogaster show that environmental factors can influence the relative fitness of certain alleles, depending on conditions like population density.
Phenotypes and genotypes are related but distinctly different concepts. The phenotype refers to the observable traits of an organism, which result from the interaction of the genotype (the organism's genetic makeup) and the environment. Mendel's hybridization experiments with plants highlight that organisms with the same phenotype can have different genotypes, and these can be influenced by various alleles interacting together, as seen in the case of human eye color involving multiple genes. Hence, it's clear that the environment plays a significant role in gene expression and the resulting phenotype.