Final answer:
The abbreviation 2n represents a diploid cell, which has two complete sets of chromosomes. It is most commonly used in discussions of meiosis, where diploid cells divide to produce haploid cells for sexual reproduction.
Step-by-step explanation:
The abbreviation 2n stands for diploid, which refers to a cell containing two sets of chromosomes. Most cells in a human body are diploid. In contrast, haploid cells, represented by n, have only one set of chromosomes. These are typically the sex cells, like sperm and eggs. When two haploid cells from each parent (sperm and egg) combine, they form a diploid zygote with chromosomes from both parents. During meiosis, a diploid cell divides to produce four haploid cells. This process is crucial for sexual reproduction as it ensures that offspring have a unique combination of genes from both parents. Meiosis includes two stages, Meiosis I and Meiosis II, resulting in haploid daughter cells with a single set of chromosomes.