Humans have 23 pairs of chromosomes, one from each parent. The most important function of chromosome is to carry the genetic material from one cell generation to the next. The basic shape of chromosomes is rod-shaped consisting of a centromere and arms. This detailed explanation will cover the structure, types, function, replication, segregation, and chemical composition of chromosomes, providing a comprehensive understanding of their role in cellular processes and inheritance. Chromosomal abnormalities occur due to the change in either chromosome number or chromosome structure. Deletion, duplication, translocation, inversion and addition are some of the structural chromosomal abnormalities while trisomy, tetrasomy and monosomy are numerical chromosomal abnormalities. Chromosome breakage is the physical breakage of subunits of a chromosome. It is usually followed by reunion (frequently at a foreign site, resulting in a chromosome unlike the original). Breakage and reunion of homologous chromosomes during meiosis are the basis for the classical model of crossing over, which results in unexpected types of offspring of a mating.
