Eukaryotic Cells versus Prokaryotic - the Stages of Meiosis

Organisms without a cell nucleus or membrane-bound organelles are referred to as prokaryotes. Although some are multicellular, they are primarily unicellular. Eukaryotes are organisms whose cells have been segmented by the cytoskeleton and internal membranes into intricate structures. Since prokaryotes derive their name from their nucleus, it is the most defining component of these organisms. Prokaryotes divide by a mechanism known as binary fission rather than mitosis or meiosis. Eukaryotic cells divide sexually during meiosis to create identical daughter cells, as opposed to prokaryotic cells, which divide vegetatively during mitosis to produce distinct cells (O'Donnell, Langston, and Stillman, 2013). The replication process of the eukaryotes is more complex as compared to the prokaryotes since they are complicated organisms. Both mitosis and binary fission are the forms of asexual reproduction in living organism. Binary fission occurs in prokaryotes and mitosis occurs in eukaryotes.

Cellular reproduction is based on the process of managing the replication of genetic material. A control mechanism is vital in ensuring the DNA and cellular components are equally distributed to new cells. Binary fission is based on a simple bipolar filament in which there is the segregation of the newly formed DNA to the opposite sides of a prokaryotic cell. Mitosis entails a complex spindle structure in separating the nuclei structures of the daughter cell.

Mitosis comprises of five separate stages: prophase, metaphase, anaphase, telophase, and cytokinesis. The prophase is characterized by chromatic condensation, dissolution of the nuclear envelope, migration and division of centrioles as well as the formation of kinetochore fibers and spindle. During metaphase, the migration of the chromosome to the equator of the spindle occurs. The spindle becomes attached to the kinetochore fiber during metaphase. During anaphase, separation of the centromeres and pulling of the chromosomes to the opposing poles of the spindle ocurrs. The chromosomes reach their poles in telophase; the following processes follow the telophase: the reformation of the nuclear envelope, the uncoiling of the chromosomes to form chromatin, and the reformation of the nucleolus. Cytokinesis is the last phase of mitosis in which new cells split. The cytoplasm is split during the process, and the allocation of organelles, such as the Golgi bodies, takes place into each new cell (Alberts, Bray, Hopkin, Johnson, Lewis, Raff & Walter, 2013).

Binary fission are simple processes that occur in prokaryotic cells. The chromosome of prokaryotes is a single DNA molecule. Binary fission is characterized by the replication of the DNA molecule and subsequent attaching each copy of the DNA to the cell membrane. The separation of the original and replicated chromosomes occurs when the cells pull apart; they eventually splits apart through the process of cytokinesis.

Despite the fact that prokaryotes and eukaryotes reproduce differently, the two process end up in cytokinesis when two identical daughter cells form. Prokaryotes reproduce asexually while eukaryotes reproduce sexually. Prokaryotes reproduce by binary fission while eukaryotes reproduce through a special type of cell division referred to as meiosis. Eukaryotes undergo the sexual reproduction through the meiosis forming haploid gametes followed by fertilization to produce a diploid zygote (Alberts et al., 2013). The mitosis and the meiosis are similar at the beginning, except the pairing up of homologous chromosomes. In meiosis, the pairing of a chromosome consists of one chromosome from each parent. Random alignment of homologous chromosome occurs during meiosis to ensure genetic diversity in sexual reproduction (O’Donnell, Langston & Stillman, 2013). Another source of genetic diversity is the trading of genetic material between paired homologous chromosomes. Although both processes end in a similar manner, meiosis produces daughter cells that are distinctly different, while mitosis produces identical cells.



References

Alberts, B., Bray, D., Hopkin, K., Johnson, A., Lewis, J., Raff, M., ... & Walter, P.

(2013). Essential cell biology. Garland Science.

O’Donnell, M., Langston, L., & Stillman, B. (2013). Principles and concepts of DNA replication

in bacteria, archaea, and eukarya. Cold Spring Harbor perspectives in biology, 5(7),

a010108.