[2026] PTE Academic Reading - Multiple Choice, Multiple Answers

Epigenetics is the study of how behaviors and environment can cause changes that affect the way genes work.Unlike genetic changes, epigenetic changes are reversible and do not change the underlying DNA sequence, but they can change how the body reads a DNA sequence.Essentially, epigenetic mechanisms act as a biological switch, turning genes on or off in response to external factors such as diet, stress, and exposure to toxins.

One of the most common and well-understood epigenetic modifications is DNA methylation.This process involves the addition of a chemical group, called a methyl group, to specific regions of the DNA molecule.When methylation occurs at a gene promoter region, it typically represses gene transcription, effectively silencing the gene and preventing the production of the associated protein.

The implications of epigenetics in human health are profound and rapidly expanding.Researchers have discovered that abnormal epigenetic patterns are heavily involved in the development of numerous diseases, including various types of cancer and neurodegenerative disorders.Because these changes are not permanent alterations to the genetic code, scientists are actively developing epigenetic therapies designed to reverse abnormal methylation and restore healthy gene expression.