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.
Neural adaptation or sensory adaptation is a change over time in the responsiveness of the sensory system to a constant stimulus. It is usually experienced as a change in the stimulus.For example, if one rests one's hand on a table, one immediately feels the table's surface on one's skin.daptation is considered to be the cause of perceptual phenomena like afterimages and the motion aftereffect. In the absence of fixational eye movements, visual perception may fade out or disappear due to neural adaptation. (See Adaptation (eye)).