Cell division is the basis of life itself; This is how animals grow and multiply.When the cells divide, two daughter cells are produced from a mother cell. Each new cell has exactly the same genetic material (DNA) as the cell in which it was produced.
Cell division has three main functions: (1) the reproduction of an entire single-celled organism, (2) the growth and repair of tissues in multicellular animals, and (3) the formation of gametes (eggs and sperm) for sexual reproduction in multicellular animals. Animals. The mitosis process produces identical cells for the first two functions listed above; The process of meiosis is gamets.
Cell division consists of two steps.First, the genome is divided by mitosis or meiosis in the nucleus. Second, the cytoplasm (the rest of the cell content) is divided. The cell is actually split into two parts, in a process called cytokinesis, in which the cell membrane is clamped in the middle like a balloon squeezed in the middle.
Most of a cell’s life is spent growing and replicating DNA.This phase in the cell cycle is called the interphase. Cells grow with materials produced within the cell using special structures called organelles. Before cell division takes place, the entire genome (the genetic material) has been copied, and there are now two complete copies in the nucleus.
Mitosis is the process of cell division that produces identical daughter cells from a mother cell.In single-celled organisms such as protists, mitosis produces two whole organisms.
There are five steps in mitosis.
Prophase.The shape of DNA changes. Other changes take place in the cytoplasm.
Prometaphase.Chromosomes begin to move because microtubules adhere to them.
Metaphase.In the middle of the cell are chromosomes drawn by microtubules. On each side of the metaphase plate there are sister chromatides. This can be compared to a left shoe on one side of the plate and a right shoe on the other side of the plate.
Anaphase pairs of sister chromatides split and are pulled through the microtubules to opposite sides of the cell.This is like putting the left shoes into different sides of the cell; the same thing happens with the right shoes. At the end of the anaphase, there is a complete set of chromosomes on each side of the cell, and the sentences are identical.
Telophase.The DNA returns to the state in which it was during the interphase.
Cytokinesis then divides the rest of the cell, resulting in two identical cells.
Meiosis is the process of cell division that produces the gametes that participate in sexual reproduction.Where mitosis produces two daughter cells from a mother cell, meiosis from a mother cell produces four daughter cells. The end products of meiosis, the gametes, contain only half of the genome of an organism. This is as if each cell ends with only a single shoe. There are no more pairs in these cells. The two gametes merge into a zygote. Since each gamete has half of the genetic material of the mother cell, this fusion leads to a zygote with the right amount of genetic material.
There are two stages of meiosis, meiosis I and meiosis II. There are five steps in Meiosis I.
Interphase I. Replication of the chromosomes, resulting in two identical sister chromatides for each chromosome.
Prophase I. Chromosomes change their shape.Homologous pairs of chromosomes, each with two sister chromatides, come together in a process called synapsis. This tetrade of chromatides is connected in several places, called Chiasmata, and there are crossings.
Metaphase I. Tetrades are located on the metaphase plate, which is still connected.
Anaphase I. Homologous chromosomes split up.Sister chromatides stay together. Microtubules pull each homologue to the opposite sides of the cell. This is like putting the left shoes on one side and the right one on the other.
telophase I and cytokinesis.The cell divides. Each cell contains a pair of sister chromatides.
Meiosis II is similar to mitosis – sister chromatids split into new cells – and the same steps take place in the same order.Chromosome pairs were split into meiosis I and sister chromatides in meiosis II. Meiosis II leads to four separate chromosomes (two pairs of sister chromatides), each packed separately. Crossing leads to slight variations between all four cells. These four cells are gamets, either eggs or sperm.
Source Laura A. Higgins