kromosomiparin

Kromosomipari, or chromosome pair, is the pair of homologous chromosomes that reside in the somatic cells of most diploid organisms. Each pair consists of one chromosome inherited from the mother and one from the father. The two members are similar in size and gene order and carry the same loci, though they may contain different alleles at many genes. Chromosome pairs form the organized units of the genome that become visible in a karyotype and are central to meiosis.

During meiosis, homologous chromosomes pair (synapse) and may exchange genetic material through crossing-over, contributing to genetic diversity in offspring. In meiosis I, the paired homologs segregate into daughter cells, reducing chromosome number by half. In mitotic divisions, sister chromatids of each chromosome are separated during anaphase, while the concept of chromosome pairs helps maintain consistent gene maps across cells. However, sister chromatids are copies of the same chromosome, whereas the chromosome pair refers to the paternal and maternal homologs.

Humans have 23 chromosome pairs in most somatic cells: 22 autosomal pairs and one sex-chromosome pair (XX in females, XY in males). Other species vary in chromosome count and sex determination systems. Abnormalities in pairing or segregation—such as nondisjunction leading to aneuploidy—can cause developmental disorders and fertility issues. Karyotype analysis and genetic mapping rely on the concept of chromosome pairs to study heredity and genome organization.