What is the primary distinction between haploid and diploid cells?

The primary distinction between haploid and diploid cells lies in their chromosome number, and option C correctly articulates this by stating that haploid cells are represented as n, which corresponds to gametes (sperm and egg cells), while diploid cells are represented as 2n, which refers to somatic cells (the body cells of an organism).

In humans, for example, gametes contain 23 chromosomes (haploid), while somatic cells contain 46 chromosomes (diploid). This distinction is crucial for understanding sexual reproduction, where haploid gametes combine during fertilization to form a diploid zygote, restoring the chromosome number. This representation of chromosome number is a fundamental concept in genetics, effectively illustrating the difference between the two cell types and their roles in biology.