What is a metaphase?
Metaphase is one of the phases of mitosis and meiosis, which are two types of cell division. During mitosis, cells that are genetically identical to the parent or clones are produced. It is used for asexual reproduction, growth of multi-cell organisms and for repairing and replacing damaged tissues. Meiosis is the division of cells used to produce cells for sexual reproduction. Mitosis happens in all cells, while meiosis occurs only in the sexual organs of the organism, such as testicles and ovaries of mammals or ovaries and antheralles of flowering plants. During mitosis there are four phases - profse, metaphase, anaphase and telophase that occur in this order. Meiosis has two divisions, Meiosis I and Meiosis II, each consisting of the same four phases as mitosis. For both processes called interifase, there is one additional phase. The interfase occurs in front of the dividemem of the phase and that is when the cells grow and are preparing to divide their DNA replications.
All cells have a cell cycle that begins when they were produced by the division of cells and ends when they divide to form identical cells. Mitosis is a period of cellular division and the rest of the cell cycle is intermediate. Interfase is commonly referred to as a resting phase, but it is a time of a lot of cellular activity. During this phase, the cell grows and produces organelles and proteins. The bottom of the core is replicated in preparation for mitosis and continues to grow and produces duplicate organelles.
During profse, chromosomes in the core are shorter and stronger, condensed and visible. Each chromosome seems to have two chromatides that are connected by centromere. Centrioles are formed and moved to the opposite ends of the cells, where microtubuly of shape called aster develops. Some of the microtubules or spindle fibers exceed the cell from the end to the end to the spindle. Finally, nucleolus and nuclear membrane are falling apart so that the chromosomes in the cytoplasm floating.
Another phase of division after a professionalis a metaphase. During this phase, the chromosomes are sorted along the center of the cell. Each of the chromosomes is connected to the spindle fiber in their centromer. Chromatides then slightly disintegrate due to the contraction of microtubules. Anaphase and then telophase follow the metaphase.
During the anaphase, the spindle fibers are completely disturbed, so that separate chromatides of each chromosome are attracted to both sides of the cell. Once the chromatids reach the poles of the cell, a new nuclear membrane is formed around them, indicating the beginning of the telofase. The spindle fibers disintegrate, the chromosomes unfold and extend, the core reforms, and the cell finally divides the intoto the two ending mitotic divisions.
meiosis is similar to mitosis, but two divisions are underway. It includes dividing chromosomes followed by two nuclear and cell divisions. Meiosis I differ from mitosis during profse, but meiosis II is a typical mitotic division, as described above. The final result of meiosis is four new cells that have half of the genetic information about the parent cell.
The key difference in meiosis occurs during profases I when the chromosome couples are connected to create a bivalent instead of creating chromatid instead of each chromosome. During the metaphase and the bivalents randomly assemble along the center of the cell to be separated. This random orientation leads to increased genetic diversity. Each pair chromosome has genes that determine the same properties, but are not always the same gene. Random distribution and independent chromosome assortment create new genetic combinations in cells.
Thechromosomes are also attracted to the opposite ends of the cells during the anaphase, and around them around them in Telophase I in Telophase I. The resulting two cells have half of the genetic material as the parent cell. Meiosis II monitors the same process as mitosis, where chromosomes form a few chromatides associated with centromere. It is aligned along the center of the cell and their centromers are attracted to the opposite end of the cell. Once they get to the poles, the cell division completes, resulting in fourNew cells, each with half of the genetic material of the original cell.