Why do cells with the same DNA have different functions?

This is because all of the cells in our bodies start from a single fertilized egg. With few exceptions, all cells in a person's body have the same DNA and genes. As cells divide and grow different genes are expressed, resulting in different cell types.

sexual reproduction produces offspring with novel combinations of genes. species that reproduce sexually must maintain two different types of individuals, males and females, which can limit the ability to colonize new habitats as both sexes must be present.

not sure if this is what you'r looking for nnew= nold