One of the chains of DNA found in cells.
Chromosomes contain genes, each encoded as a subsection of the DNA chain.
Chromosomes are usually present in all cells in an organism, even though only a minority of them will be active in any one cell. The exchange of nucleotides between pairs of homologous chromosomes during mitosis or especially meiosis. A gene is said to be epistatic when its presence suppresses the effect of a gene at another locus. Epistatic genes are sometimes called inhibiting genes because of their effect on other genes which are described as hypostatic. Change in allele frequency in a population over time.