What is epigenetics?

The selected answer is accurate because epigenetics specifically refers to the study of how chemical modifications to DNA and associated proteins regulate gene expression without altering the underlying DNA sequence. This means that while the genetic code remains unchanged, factors such as environment, lifestyle, and experiences can influence how genes are turned on or off. This has significant implications for understanding development, behavior, and the potential for diseases, as it highlights that genetics is not solely deterministic; environmental factors play a crucial role in shaping how genetic information is expressed.

The other options, while related to various aspects of psychology and development, do not encapsulate the concept of epigenetics. For instance, assessing child characteristics influencing parenting behaviors pertains to behavioral genetics and parental influence rather than the molecular mechanisms of gene expression. Similarly, the mention of genetic factors contributing to variations in the environment relates more to the interaction of genetics and environment, which is a broader topic than epigenetics. Finally, the first stage of the memory system is a cognitive psychology concept, distinct from the biological basis of gene expression characterized by epigenetics.