Replication Error Definition
Replication Error – a mistake that occurs when DNA sequences duplicate before cell division. Replication errors are accountable for CHROMOSOMAL DISORDERS such as AUTOSOMAL TRISOMY, in which a GAMETE (also called a sex cell or germ cell) receives two copies of a CHROMOSOME instead of the normal single copy. Gametes, which are haploid cells, each carry one-half the complement of chromosomes so when they unite to form the ZYGOTE that will become a new human being, the zygote contains the full complement of genetic material.
With a replication error such as an autosomal trisomy, the zygote receives an extra chromosome two copies from one gamete and one copy from the other gamete. The result is a chromosomal disorder such as DOWN SYNDROME. Replication errors also may have harmless consequences when they occur in DNA sequences that do not encode structural or regulatory sequences of gene activity.