What does the term "epigenome" refer to?

The term "epigenome" specifically refers to the various chemical modifications that occur on the DNA and the proteins associated with it, which can influence gene expression without altering the underlying DNA sequence. This process is heavily influenced by environmental factors, such as diet, stress, and exposure to toxins, which can lead to changes in how genes are turned on or off.

Through these modifications, the epigenome essentially acts as a regulatory layer that controls gene expression patterns, enabling cells to respond dynamically to their environment. Thus, the correct answer captures the essence of how external factors can shape and modulate genetic information, distinguishing it from other biological concepts that focus solely on DNA mutations, molecular interactions, or inherited gene sequences.