Question

in the body, why do muscle cells and skin cells look and behave differently?
o they have different genes.
o their genes are being expressed differently.
o there is no similarity in their chromosomes.
o the same genes are being expressed in both types of cells.

Explanation:

• All cells in the body (except gametes) have the same genes and chromosomes. So options "They have different genes" and "There is no similarity in their chromosomes" are incorrect.
• If the same genes were expressed in both muscle and skin cells, they would look and behave similarly. But they don't. So option "The same genes are being expressed in both types of cells" is wrong.
• Gene expression (which genes are turned on or off) determines cell structure and function. Muscle and skin cells express different sets of genes, leading to their different looks and behaviors.

Answer:

Their genes are being expressed differently.