What is the purpose of the diploid cell?

A diploid cell is the result of the combination of two parental cells. For example, via meiOSis in humans, different chromosomes are extracted from both parents which then combine into creating 23 chromosome pairs for fetus. Diploid cells are commonly referred to as "2n", as Haploid are "n". In humans, this stands for 2n = 46, which is our total number of chromosomes.

Diploid cells are what cause genetic variation among populations due to the fact that they combine different chromosomes from different receptors