mitotic phase

Examples of mitotic phase in the following topics:

• Interphase

  • In order for a cell to move from interphase into the mitotic phase, many internal and external conditions must be met.
  • Some cell organelles are duplicated, and the cytoskeleton is dismantled to provide resources for the mitotic phase.
  • The cell cycle consists of interphase and the mitotic phase.
  • Interphase is followed by the mitotic phase.
  • During the mitotic phase, the duplicated chromosomes are segregated and distributed into daughter nuclei.

• The Mitotic Phase and the G0 Phase

  • During the multistep mitotic phase, the cell nucleus divides, and the cell components split into two identical daughter cells.
  • The mitotic phase is a multistep process during which the duplicated chromosomes are aligned, separated, and move into two new, identical daughter cells.
  • The first portion of the mitotic phase is called karyokinesis or nuclear division.
  • The second portion of the mitotic phase, called cytokinesis, is the physical separation of the cytoplasmic components into the two daughter cells.
  • Not all cells adhere to the classic cell cycle pattern in which a newly-formed daughter cell immediately enters the preparatory phases of interphase, closely followed by the mitotic phase.

• The Role of the Cell Cycle

  • The cell cycle has two major phases: interphase and the mitotic phase .
  • During the mitotic phase, the replicated DNA and cytoplasmic contents are separated and the cell divides.
  • The cell cycle consists of interphase and the mitotic phase.
  • Interphase is followed by the mitotic phase.
  • During the mitotic phase, the duplicated chromosomes are segregated and distributed into daughter nuclei.

• Regulation of the Cell Cycle at Internal Checkpoints

  • A cell that does not meet all the requirements will not progress to the S phase.
  • The cell can halt the cycle and attempt to remedy the problematic condition, or the cell can advance into G0 (inactive) phase and await further signals when conditions improve.
  • If a cell meets the requirements for the G1 checkpoint, the cell will enter S phase and begin DNA replication.
  • The G2 checkpoint bars entry into the mitotic phase if certain conditions are not met.
  • If the DNA has been correctly replicated, cyclin dependent kinases (CDKs) signal the beginning of mitotic cell division.

• Centrosome

  • In mitosis the nuclear membrane breaks down and the centrosome nucleated microtubules (parts of the cytoskeleton) can interact with the chromosomes to build the mitotic spindle .
  • The centrosome replicates during the S phase of the cell cycle .
  • The mitotic spindle then forms between the two centrosomes.
  • The centrosome replicates during the S phase of the cell cycle.
  • The mitotic spindle then forms between the two centrosomes.

• Animal Reproduction and Development

  • However, a few groups, such as cnidarians, flatworms, and roundworms, undergo asexual reproduction, although nearly all of those animals also have a sexual phase to their life cycle.
  • The process of animal development begins with the cleavage, or series of mitotic cell divisions, of the zygote .
  • During embryonic development, the zygote undergoes a series of mitotic cell divisions, or cleavages, to form an eight-cell stage, then a hollow blastula.

• Binary Fission

  • The precise timing and formation of the mitotic spindle is critical to the success of eukaryotic cell division.
  • Prokaryotic cells, on the other hand, do not undergo karyokinesis and, therefore, have no need for a mitotic spindle.
  • However, the FtsZ protein that plays such a vital role in prokaryotic cytokinesis is structurally and functionally very similar to tubulin, the building block of the microtubules that make up the mitotic spindle fibers that are necessary for eukaryotes.
  • A survey of mitotic assembly components found in present-day unicellular eukaryotes reveals crucial intermediary steps to the complex membrane-enclosed genomes of multicellular eukaryotes.

• Interpreting Phase Diagrams

  • The lines that separate these single phase regions are known as phase boundaries.
  • By focusing attention on distinct single phase regions, phase diagrams help us to understand the range over which a particular pure sample of matter exists as a particular phase.
  • When evaluating the phase diagram, it is worth noting that the solid-liquid phase boundary in the phase diagram of most substances has a positive slope.
  • With a knowledge of the major components of phase diagrams and the features of phase plots, a phase diagram can be used to understand how altering thermodynamic parameters influences the states/phases of matter a sample of a substance is in.
  • A typical phase diagram illustrating the major components of a phase diagram as well as the critical point.

• Comparing Meiosis and Mitosis

  • The nuclei resulting from a mitotic division are genetically identical to the original nucleus.
  • Meiosis II is much more similar to a mitotic division.
  • During anaphase II and mitotic anaphase, the kinetochores divide and sister chromatids, now referred to as chromosomes, are pulled to opposite poles.

• Major Features of a Phase Diagram

  • A phase diagram is a graph which shows under what conditions of temperature and pressure distinct phases of matter occur.
  • The simplest phase diagrams are of pure substances.
  • The major features of a phase diagram are phase boundaries and the triple point.
  • Phase boundaries, or lines of equilibrium, are boundaries that indicate the conditions under which two phases of matter can coexist at equilibrium.
  • In this phase diagram, which is typical of most substances, the solid lines represent the phase boundaries.