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.
For example, they may adjust their crawling or walking in response to the rigidity, slipperiness, or slant of surfaces (Adolph 1997). Motor movements, including movements of the eyes, arms, legs, and hands, provide most of the perceptual information infants receive (Adolph and Berger 2006).