HUMAN MEIOSIS

Human Meiosis

Human Meiosis

Plan for this Essay

In this essay following are the points which will be discussed:

First introduction will be given in which Meiosis process life cycle will be defined.

Secondly in discussion brief meiosis divisions are mention.

Then the paper discusses meiotic double-stranded break (DSB) formation and processing.

Finally it discusses the medical consequences of failure to correctly segregate meiotic chromosomes.

Human Meiosis Essay

Meiosis is a form of cell reproduction. This process takes place in the sexual glands for the production of gametes (Gerton & Hawley, 2005: 477). Division is a process of cell in which a diploid cell (2n) undergoes two successive divisions, with the ability to generate four haploid cells (n). In organisms with sexual reproduction is important as it is the mechanism that produced the eggs and sperm. This process is carried out at two nuclear and cytoplasmic divisions, called first and second meiotic division or simply meiosis I and meiosis II. Both include prophase, metaphase, anaphase and telophase.

Sexually reproductive organisms utilize meiosis to produce gametes (e.g. egg and sperm). During meiosis, chromosome numbers reduce to half (haploid) and fertilization restores their numbers to a diploid state so that ploidy can be maintained throughout generations. Meiosis involves two successive divisions (meiosis I and meiosis II) that follow a single round of DNA replication. In meiosis I homologous chromosomes segregate, whereas in meiosis II sister chromatids segregate.

Proper segregation of chromosomes during meiosis requires the formation and repair of double-strand breaks (DSBs) to form crossovers. Repair is biased toward using the homolog as a substrate rather than the sister chromatid. Pch2 is a conserved member of the AAA+-ATPase family of proteins and is implicated in a wide range of meiosis-specific processes including the recombination checkpoint, maturation of the chromosome axis, crossover control, and synapsis (Marston & Amon, 2004: 993). 

Pch2 play role in promoting and regulating inter-homolog bias and the meiotic recombination checkpoint in response to unprocessed DSBs through ...