|
Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. Most somatic cells (body cells) of higher organisms are diploid or polyploid (three or more copies of each chromosome, often found in plants), whereas their reproductive cells are usually haploid (they have only one copy of each chromosome). During meiosis, germ cell precursors have their number of chromosomes halved by randomly "choosing" one homolog, resulting in haploid germ cells (sex cells or gametes).
When reproducing sexually, gametes of both parents will generally merge to form a diploid cell, the zygote, with unique genetic properties, which then develops into the next developmental stages.
See also
|
