Cytokinesis is similar in both animal and plant cells and involves the constriction of a ring of actin filaments. Most chromosomes are condensed into easily visible structures only during mitosis and meiosis. Phosphorylation of proteins is very rare, but the cdc2 kinase that regulates the cell cycle is one of the few proteins that is regulated in this way. Chromosomes are moved by microtubules in both animal and plant cells. At metaphase of mitosis, the centromere of each chromosome is connected to each spindle pole.
Chromatids become chromosomes when the centromeres split at the metaphase-anaphase transition.
Meiosis involves two rounds of cell division, but only one round of DNA replication. Two parents with pointed ears must have only children with pointed ears. A diploid animal can only have two alleles of any given gene. The distance between two nearby genes on the same chromosome can be measured by determining the frequency of recombination between the genes during meiosis. All of the F1 progeny have pink flowers.