is the cell division process that generates genetically identical daughter cells. All somatic cells and stem germ cells (spermatogonia/oogonia) proliferate by mitotic cell division.
involves a two stage cell division (Meiosis I followed by Meiosis II). By means of meiosis, primary spermatocytes & oocytes generate haploid gametes (sperm & ova) that are unique regarding genotype.
Beginning with the zygote, all cell divisions in an animal are mitotic excepts for the germ cell divisions that produce gametes by meiosis.
: a copy of a chromosome. Following mitosis (prior to synthesis during interface), each chromosome consists of one chromatid. Following synthesis, each chromosome is composed of two chromatids linked by a centromere.
: refers to stained chromosomes within the nucleus of a eukaryotic cell; inactive chromosomes stain distinctly (heterochromatin) but active chromosomes are uncoiled and do not stain distinctly (euchromatin).
: double-stranded DNA and associated histone proteins located within the nucleus of a eukaryotic cell.
: refers to genotypically similar chromosomes that constitute a paternal-maternal pair; the two are linked together during Meiosis I (predisposing to crossover exchange of genes).
(2N): refers to the typical number of chromosomes found in all body cells except secondary germ cells and gametes; chromosomes are present as homologous pairs in diploid cells.
(N): refers to the number of chromosomes found in
secondary germ cells and gametes; individual chromosomes are represented by either the paternal or maternal chromosome per homologous pair.
: refers to the period in the cell cycle when synthesis occurs in preparation for mitosis or meiosis I; synthesis produces two chromatids per chromosome during interphase.
: refers to germ cell divisions that give rise to four gametes that are haploid with unique genotypes (meiosis I
produces haploid daughter cells and meiosis II
generates unique gametes).
: refers to the typical cell division that gives rise to two daughter cells, each have the same genotype as the parent cell.