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.
Perceptual mapping is a marketing research technique used to compare different product brands across the two or more dimensions. A typical technique is to map the similarities between the products perceived by the research subjects.ere's an example of a perceptual map of similarity: Another approach is use of preference data. You can collect data based upon a comparison of two products or rankings of several products.