Mitosis is the process by which a cell duplicates the chromosomes in its cell nucleus, in order to generate two, identical, daughter nuclei. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two daughter cells containing roughly equal shares of these cellular components. Mitosis and cytokinesis together define the mitotic (M) phase of the cell cycle, the division of the mother cell into two daughter cells, each with the genetic equivalent of the parent cell. Mitosis is the process by which a cell duplicates the chromosomes in its cell nucleus, in order to generate two, identical, daughter nuclei. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two daughter cells containing roughly equal shares of these cellular components. Mitosis and cytokinesis together define the mitotic (M) phase of the cell cycle, the division of the mother cell into two daughter cells, each with the genetic equivalent of the parent cell. Mitosis occurs exclusively in eukaryotic cells, but occurs in different ways in different species. For example, animals undergo an "open" mitosis, where the nuclear envelope breaks down before the chromosomes separate, while yeast such as Saccharomyces cerevisiae and fungi such as Aspergillus nidulansundergo a "closed" mitosis, where chromosomes divide within an intact cell nucleus.[1] In multicellular organisms, the somatic cells undergo mitosis, while germ cells - cells destined to become sperm in males or ova in females - divide by a related process called meiosis. Prokaryotic cells, which lack a nucleus, divide by a process called binary fission. The process of mitosis is complex and highly regulated. The sequence of events is divided into phases, corresponding to the completion of one set of activities and the start of the next. These stages are prophase, prometaphase, metaphase, anaphase and telophase. During the process of mitosis the pairs of chromosomes condense and attach to fibers that pull the sister chromatids to opposite sides of the cell. The cell then divides in cytokinesis, to produce two identical daughter cells. Because cytokinesis sis occurs exclusively in eukaryotic cells, but occurs in different ways in different species. For example, animals undergo an "open" mitosis, where the nuclear envelope breaks down before the chromosomes separate, while yeast such as Saccharomyces cerevisiae and fungi such as Aspergillus nidulans undergo a "closed" mitosis, where chromosomes divide within an intact cell nucleus.[1] In multicellular organisms, the somatic cells undergo mitosis, while germ cells - cells destined to become sperm in males or ova in females - divide by a related process called meiosis. Prokaryotic cells, which lack a nucleus, divide by a process called binary fission. The process of mitosis is complex and highly regulated. The sequence of events is divided into phases, corresponding to the completion of one set of activities and the start of the next. These stages are prophase, prometaphase, metaphase, anaphase and telophase. During the process of mitosis the pairs of chromosomes condense and attach to fibers that pull the sister chromatids to opposite sides of the cell. The cell then divides in cytokinesis, to produce two identical daughter cells
A cell is usually induced into meiosis from the G1 stage of interphase by the presence of a chemical or hormone. Then the cell must pass certain checkpoints in the cell cycle to actually undergo meiosis.
They mate.
DNA replicates and forms tetradโAPEX.
Meiosis I and meiosis II
Meiosis
Gametes are produced by a type of cell division called meiosis. Meiosis results in four daughter cells each with half the number of chromosomes of the parent cell.
Meiosis allows a cell to form into 4 cells (by meiosis 1 (which is literally mitosis) and meiosis 2 (mitosis without DNA replication)) in meiosis 1, the cells exchanges DNA information between homologous pairs, this allows genes to be transferred and creates 4 unique and distinct cells. segragation of alleles occur too.
A duplication of the chromosomes is what must happen before meiosis can begin.
Introphase
DNA replicates and forms tetradโAPEX.
they have to duplicate
They mate.
puberty
They must double
A nucleus is signals the rest of the cell that the cell is ready to undergo meiosis, in which case the chromosomes begin to condense with the help of histones, which is the beginning of prophase I of meiosis.
A duplication of the chromosomes is what must happen before meiosis can begin.
Interphase. The process of meiosis has many similarities to the process of mitosis: chromosomes replicate before the process begins, and shorten and thicken to look like the chromosomes at the beginning of mitosis (condensation).
Both processes begin with similar events, including chromosome replication.
Meiosis I and meiosis II