The colonies that developed were red, with the exception of one colony that was white. A garden hose that had been lying on a green lawn for several days was removed. The lack of sunlight under the hose altered the genotype of the grass. Gene expression is not affected by the environment. The lack of sunlight under the hose affected chlorophyll production.
Artificial selection is illustrated by random mating taking place in a population.
The gene-chromosome theory states that chromosomes from both parents always have identical genes. Mendel's principles no longer apply to genetics. All of the offspring produced in a cross involving a brown mink and a silver-blue mink are brown. The results of these crosses are best explained by independent assortment and crossing-over dominance, segregation, and recombination. Biologically similar organisms have similar DNA and proteins.