The kinetochore is the centre of the chromosome. The third stage metaphase involves the chromosomes aligning themselves on the metaphase plate ready to enter anaphase. Then anaphase is where the centromeres divide and each sister chromatid is moved to opposite poles of the cell. The spindle fibres are involved in this. They are now referred to as daughter chromosomes.
That is when the nucleus divides to form two identical nuclei. The second step taken would be prophase. That is when chromoso... ... middle of paper ... ... again and again each time the cell replicates through mitosis. That is because the daughter cell has identical genetic information as the mother cell. As you can see, DNA is a very important part of life.
The actual division occurs during the S phase bur the G phases are mainly for the purpose of growing. Starting with the G1 phase the cell grows in preparation for certain intracellular components and DNA replication. This phase makes sure the cell is prepared for the process of DNA replication. It reviews the size and environment to ensure that is it ready to go, and cannot leave the G1 until it is complete. But what happens to a cell when it is not complete and cannot exit out of the phase?
c. The creation of genetic variety by crossing over between homologous chromosomes During prophase 1 of meiosis, equal portions of homologous chromosomes may be swapped. In this way new genetic combinations are made and linked genes separated. The variety which meiosis brings vital for to the process of evolution. By providing a varied stock of individuals it allows the natural selection of those best suited to the existing conditions and makes sure that species constantly change and adapt when these conditions change. This is the main biological significance of meiosis.
Instead of lining up on a metaphase, as in mitosis, chromosomes come together in pairs (2). Each chromosome in a pair is similar in structure (homologous), but would have come originally from different parents. Later in propha... ... middle of paper ... ...hese daughter chromosomes then begin to separate from each other, each moving away from the metaphase plate and toward one of the two spindle pole regions. The mechanisms that control chromosome separation clearly involve the interactions between microtubules and components in or near the kinetochore. Sometime after anaphase onset, the chromosomes have moved close to the spindle pole regions, and the spindle middle begins to clear.
Cellular Reproduction Cellular Reproduction is the process by which all living things produce new organisms similar or identical to themselves. This is essential in that if a species were not able to reproduce, that species would quickly become extinct. Always, reproduction consists of a basic pattern: the conversion by a parent organism of raw materials into offspring or cells that will later develop into offspring. (Encarta, 2) In almost all animal organisms, reproduction occurs during or after the period of maximum growth. (Fichter, 16).
The next stage is metaphase 2 the chromosomes line up along the center of the cell before it breaks up into two. Then the chromatids point towards the opposite ends of the cell. The next stage is anaphase 2. This is the second to last phase in meiosis and it has many events that happen. The first event is when the sister chromatids separate and move towards the opposite ends of the pole.
Mitosis and meiosis both occur in the M phase of the cell cycle, and are the methods of cell division to form somatic cells and gametes, respectively. They are both complex processes that form more than one daughter cell from one parent cell, and they have many similarities and differences, which will be discussed in this essay. Mitosis is the type of cell division that occurs in all somatic cells. Its purpose is to produce two genetically identical daughter cells. Before the process of mitosis starts, DNA replicates and the resulting sister chromatids are held together by cohesin proteins.
In anaphase I the homologs move to opposite ends of the poles and the homologs also begin to separate as well. In telophase I the sister chromatids appear and each have a full set of duplicated chromosomes. Then following telophase I, prophase II occurs which is when the spindle apparatus begins to appear and the two chromatids begin to the metaphase II
Discuss the processes of mitosis and meiosis that occur during the M phase of the cell cycle, including their similarities and differences. The cell cycle is an undeniably fundamental part in the journey of a cell. Without it there would be no cell reproduction or growth. Through the process of mitosis and also meiosis which will be shortly discussed about, it will come to be known exactly just how important it actually is. Mitosis is described as a type of cell division.