This page discusses endoreplication, a process of DNA replication during the S phase without mitosis or cytokinesis, found in some animal and plant cells. Variants include replication with mitosis but...This page discusses endoreplication, a process of DNA replication during the S phase without mitosis or cytokinesis, found in some animal and plant cells. Variants include replication with mitosis but no cytokinesis and multiple rounds of replication without new nuclei. This can cause polyploidy or polyteny, the latter evident in Drosophila larva, where polytene chromosomes allow for gene amplification and increased expression.