Final answer:
The symbol 2n represents a diploid cell with two sets of chromosomes and is used for somatic cells, while n denotes a haploid cell with one set of chromosomes, typical for gametes. During sexual reproduction, haploid cells combine to form a diploid zygote.
Step-by-step explanation:
The symbols 2n and n relate to the number of sets of chromosomes in a cell. The symbol 2n denotes a diploid cell, one with two sets of chromosomes, which is typical for somatic cells in an organism. The symbol n refers to a haploid cell, which has only one set of chromosomes, typical for gametes like sperm and eggs. Haploid cells merge during fertilization to form a diploid zygote, effectively restoring the diploid state with genetic contributions from both parents.
In humans, a diploid cell contains 46 chromosomes, while a haploid gamete has 23. This distinction is critical for the process of sexual reproduction, ensuring that offspring have the correct number of chromosomes. The alternation of generations, seen in the life cycle of plants, involves transitions between haploid and diploid stages, specifically the gametophyte (haploid) and sporophyte (diploid).