The Methylation State of an Individual CpG Island

Question

The methylation state of an individual CpG island:
A)is fixed; such genes are permanently turned off.
B)is fixed, but this has no effect on whether genes are expressed.
C)is random-sometimes the cytosines are methylated and sometimes they're not, but the state is independent of the environment or cell type.
D)can change over time in response to environmental cues, allowing genes to be turned on or off as needed.
E)can change over time in response to environmental cues, but this has no effect on gene expression.

Accepted Answer

The methylation state of an individual CpG island can change over time in response to environmental cues, allowing genes to be turned on or off as needed. This process is known as epigenetic regulation and plays a critical role in development, differentiation, and adaptation to changing environmental conditions. However, it should be noted that not all CpG islands are equally susceptible to epigenetic changes and some may be more stable or resistant to modification.