Epigenetics role in gene-environment interactions?

• A. Changes DNA sequence
• B. Epigenetic modifications do not affect development
• C. Epigenetics occurs only in adults
• D. Alters gene expression without changing DNA

Answer: (D)

Environmental factors can influence how genes are expressed through epigenetic mechanisms that don't alter the DNA sequence. Epigenetics involves chemical tags and structural changes—like DNA methylation or histone modification—that can turn genes on or off in specific tissues and times. These marks respond to environment, such as nutrition, stress, toxins, or social experiences, shaping development and later health outcomes without changing the underlying genetic code. That’s why the correct description is that epigenetics alters gene expression without modifying DNA. The other ideas aren’t accurate because changing the DNA sequence would be a genetic mutation, epigenetic changes do affect development, and such modifications can occur across the lifespan, not only in adulthood.