Biological Systems MCAT Practice Exam

Which process involves the transformation of unspecialized cells into specialized cell types?

1. Migration

2. Cell differentiation

3. Apoptosis

4. Senescence

The correct answer is: Cell differentiation

Cell differentiation is the process through which unspecialized cells, such as stem cells, undergo a series of changes that lead them to develop into specialized cell types with distinct structures and functions. This process is crucial during development, allowing the formation of various tissues and organs in a multicellular organism. During cell differentiation, unspecialized cells respond to intrinsic signals, such as the activation of specific genes, as well as extrinsic signals from their environment, including growth factors and chemical cues. These signals orchestrate a cascade of gene expression changes that ultimately define the identity and function of the specialized cells, such as muscle cells, nerve cells, or blood cells. In contrast, migration refers to the movement of cells from one location to another, which can occur during development or repair processes. Apoptosis is programmed cell death, an essential mechanism that allows for the removal of unnecessary or damaged cells, while senescence involves the loss of a cell’s ability to divide and function, often as a response to stress or damage over time. Neither of these processes directly leads to the transformation of cell types, making cell differentiation the key answer in this context.