Binary fission is a form of asexual reproduction used by prokaryotes (organisms with no nucleus) such as bacteria and some forms of protozoa. Daughter chromosome formation begins when the DNA molecule replicates and the copies attach to opposite ends of the plasma membrane. The plasma membrane grows inward and splits apart. A cell wall forms, producing two identical daughter cells.
Mitosis, or somatic division, produces two daughter cells identical to the parent cell. Mitosis allows eukaryotic organisms (with a nucleus) to grow and also repair tissue. Plants use mitosis to reproduce vegetatively, thereby producing clones. Either haploid (one complete set of chromosomes) or diploid cells (two complete sets of chromosomes) can divide by mitosis, with haploid cells producing haploid daughter cells and diploid cells producing diploid daughter cells. Each daughter chromosome contains identical genetic material from the parent cell.
Meiosis, or sexual division, produces haploid cells that have one-half the number of chromosomes. Meiosis occurs in animals when gametes (eggs and sperm) are formed. Plants do not form gametes; instead, meiosis occurs via spore formation. The spores then divide by mitosis. Meiosis is differentiated by the same phases as mitosis, but has two cycles. The first cycle reduces the number of chromosomes by half while the second cycle duplicates the chromosomes without reducing their number.
Both eukaryotes and prokaryotes divide through the process of replication, segregation and cell splitting. Cell division in eukaryotic organisms starts when DNA strands (chromatids) replicate during interphase and coil and form spindles during prophase. Then, they migrate to middle of spindle during metaphase and split into daughter chromosomes during anaphase. Binary fission is not divided into phases because prokaryotes have no nucleus (membrane-bound organelle) or centromere (area where chromosomes attach and spindle forms). During the final phase, telophase, the daughter chromosomes reach the poles and cell splitting occurs.