A comprehensive introduction to key biological concepts tested on the MCAT, focusing on cellular processes, genetics, and the integration of biological systems.
Not all genes are active all the time. Cells use gene regulation to control which genes are expressed, and when. This allows for specialization—like muscle cells vs. nerve cells—even though all cells have the same DNA!
Epigenetics explains why identical twins can look and act differently, and why environmental factors (like diet or stress) can affect gene expression.
Epigenetic changes can play roles in cancer, mental illness, and inheritance patterns not explained by DNA sequence alone.
Cancer cells often have abnormal DNA methylation, turning off genes that control cell growth.
Childhood nutrition can lead to lasting epigenetic changes affecting health in adulthood.
Gene regulation and epigenetics let cells fine-tune gene activity, shaping development and health.