Final answer:
Maternal inheritance of mitochondria is an example of epigenetics in biology.
Step-by-step explanation:
An example of epigenetics is maternal inheritance of mitochondria. Mitochondria are inherited from the mother, meaning that traits encoded by mitochondrial DNA are passed down from the mother to her offspring. This is a form of epigenetic inheritance as it involves the transmission of heritable changes in gene expression without changes to the underlying DNA sequence.