Chromosomes are divided into sexual and non-sexual (autosomes). Sex chromosomes are a pair of chromosomes that differ in males and females of the same species. In one of the sexes, as a rule, these are two identical large chromosomes (X chromosomes, genotype XX); the other has one X chromosome and one smaller Y chromosome (genotype XY). In some species, the male sex is formed in the absence of one sex chromosome (genotype X0). Autosomes are pairs of chromosomes that are identical in individuals of the same biological species belonging to different sexes. The number of pairs of autosomes is equal to the number of pairs of chromosomes in the genotype minus one (one pair of sex chromosomes). So, a person has 22 pairs of autosomes, and Drosophila has 3 pairs. All autosomes of each biological species are given serial numbers in accordance with their size (the first is the largest; the last is the shortest and, therefore, carries the least number of genes)
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.