Answer:
The given blank can be filled with epigenetics.
Step-by-step explanation:
The study of inherited alterations in gene expression, which do not comprise modifications to the principal sequence of DNA is known as epigenetics. It refers to a variation in phenotype without modification in genotype that in turn influences how the cells read the genes.
Epigenetic change refers to a natural and regular happening, however, it can also be affected by many elements like the environment or the lifestyle, age, and disease state.