DNA methylation is used in some genes to differentiate which gene copy is inherited from the father and which gene copy is inherited from the mother, a phenomenon known as imprinting. Histones are proteins that are the primary components of chromatin, which is the complex of DNA and proteins that makes up chromosomes.his is the type of epigenetic change that is responsible for the inactivated X chromosome of females. In contrast, methylation of a different lysine (K4) on the same histone (H3) is a marker for active genes (Egger et al ., 2004).
Perceptual adaptation is a phenomenon that occurs for all of the senses, including smell and touch. An individual can adapt to a certain smell with time.
Adaptation. An adaptation is a feature that is common in a population because it provides some improved function. Adaptations are well fitted to their function and are produced by natural selection. vestigial structure is a feature that was an adaptation for the organism's ancestor, but that evolved to be non-functional because the organism's environment changed. Fish species that live in completely dark caves have vestigial, non-functional eyes.