Final answer:
Cells in the body generally contain the same DNA, but differ in their structure and function due to the differential expression of genes.
Step-by-step explanation:
Each somatic cell in the body generally contains the same DNA. However, cells can differ in their structure and function because not all genes are expressed in every cell. The expression of different genes in the DNA leads to specialization and differentiation of cells. For example, the nucleus of a cell in your thigh muscle contains the same genes as the nucleus of a cell in your brain, but different genes are expressed in each cell type, resulting in their unique characteristics and functions.