Answer:
D) epigenetic phenomena.
Step-by-step explanation:
All that a living being is, anatomically and functionally, even in its behavior, is determined by the genes that in a very complex interaction with the environment build living beings. Genes articulate the responses of cells (and therefore of the organisms that carry them) to environmental stimuli, interaction with other genes (of other cells and other living things) and fundamentally direct the self-construction of any living being.
The genes regulate themselves, establishing a very sophisticated kind of program, with very precise spatial and temporal dimensions. How this regulation is achieved, what principles guide it is the subject of the study of molecular biology. But genes are also transferred from one generation to another. The cells divide and inherit their genes to the offspring. Other cells - gametes - carry the information to be inherited from parents to children or from generation to generation. What rules genes follow in this path of inheritance of individuals, species, populations, is the subject of study of genetics.
Genes are constructed of DNA (acronym that names deoxyribonucleic acid). The total gene content of an individual is called a genotype and the effect that the genotype activity causes on the individual (appearance, structure, functioning) we call it a phenotype. The mechanisms of functioning and regulation of genes involve chemical activity on DNA, including changes in its sequence (mutations). Epigenetic phenomena are defined as any change in gene expression (change in phenotype) that is inheritable but does not involve DNA mutations (genotype modifications). Epigenetics refers to any process of regulation of genes that do not imply changes in the DNA sequence. If the DNA contains information (genes), epigenetics deals with the genetic information that is outside the genes.