Final answer:
The 22 pairs of chromosomes that are not related to sexual expression in humans are called autosomal chromosomes. These contain genes that determine various traits and are identical in both males and females, except for the sex chromosomes.
Step-by-step explanation:
The 22 pairs of chromosomes in humans that are not involved in determining the sex of an individual are known as autosomal chromosomes. These chromosomes are numbered from 1 to 22 and carry genes that code for a vast array of characteristics and traits that are unrelated to the sexual characteristics of an individual. Both males and females have the same set of autosomal chromosomes, making them identical in both sexes.
Each autosome contains hundreds or thousands of genes, contributing to an individual's genotype, which in turn expresses the phenotype. Unlike the sex chromosomes (XX in females and XY in males), which are the 23rd pair, autosomes do not contain genes that determine the sex of an individual. Additionally, errors in the number of autosomes, such as monosomy or trisomy, can result in developmental challenges, with Down Syndrome being an example of trisomy 21.