Notes on Mitosis Cell Division | Grade 10 > Science > Chromosome and Sex Determination | KULLABS.COM

Mitosis Cell Division

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Points to remember:

  • Spindle fibre: The proteneous threads, which are produced during metaphase stage of cell division, are called spindle fibre. They help in the movement of the chromosome.
  • Chromosome: When two chromatid threads are attached with one another through centromere is called chromosome.
  • Centromere: The point where two chromatin fibres attach with each other is called centromere.
  • Chromatid: When we separate the two thread of chromosome then the individual thread is called chromatid.

Process of cell division:

  1. Interphase:
    • It is not the actual stage of cell division but is the resting stage of cell in which it prepares itself for further division.
    • All cellular organelles are present and are well flourishing.
    • The chromosomes are not seen directly.
  2. Prophase:
    • Centriole divides into two and each one move towards the opposite pole of the cell.
    • Chromosomes are thicker and shorter and can be seen clearly.
    • In late prophase except centriole, chromosome and cell membrane, other parts disappear.
  3. Metaphase:
    • Centrioles are at the opposite poles of the cell.
    • Chromosomes are arranged in the equatorial plane of the cell.
    • Spindle fiber appears which help the chromosome to lie in equatorial
  4. Anaphase:
  • Chromosome split length wise through centrosome. So sister chromosomes called chromatids are produced.
  • Eachchromatidsstart to move towards the opposite poles of the cell by contraction of the spindle fibre and repulsive force between chromatids.
  • In thisstavechromosome appears in I, J,U and V shape.
  1. Telophase:
    • The chromatids have already reached to opposite poles of the cell.The nuclear membrane is synthesized enclosing the chromosomes.
    • Cellular construction becomes more and deeper and finally divides the cell into two equal halves.
    • Cellular organelles reappear.

http://www.nanoiv.com/images/cellimaging5.jpg

Cytokinesis: The change that occurs in the cytoplasm (cell membrane) during the process of cell division is called cytokinesis. Anaphase and telophase of cell division lie under cytokinesis.

Karyokinesis: The change that occurs in chromosome during the process of cell division is called karyokinesis. All four stage of cell division i.e. prophase, metaphase, anaphase and telophase fall under karyokinesis.

Importance of mitosis cell division

  • Physical growth: Mitosis cell division occurs only in the somatic cell, which helps to increase the number of cells in a body resulting physical growth.
  • Asexual reproduction: Minor animals and plants, which reproduce by anasexual method, follow the process of mitosis cell division.
  • Regeneration and healing wounds: The wounded part of the body will be repaired by the mitosis cell division. Some animals and plants have the unique ability to gain last body part. This is possible because of mitosis.
  • Genetic stability: The daughter cells produces at the end of the mitosis are similar to their mother in all respect. Therefore, it helps to keep genetic stability.



  • Mitosis is divided into interphase, prophase, metaphase, and telophase.
  • Mitosis cell division helps in asexual reproduction, growth, healing wounds and genetic stability.
  •  Mitosis cell division occurs only in the somatic cell
.

Very Short Questions

The incidents that take place during the prophase stage of mitotic cell division are:
i. The chromosomes coil, shorten and become distinct.
ii. Each chromosome divides longitudinally to form two chromatids that are held together by a centromere.
iii. In animal cells, the centrioles divide and move towards opposite poles.
iv. Nucleons and nuclear envelop begin to disappear.

The incidents that occurred at anaphase of mitotic cell division are:
a. The spindle fibers contract.
b. The centromere splits.
c. The chromatids separate.
d. The chromatids move to opposite poles.

The significances of mitotic cell division are:
a. It is used for growth and development of an organism.
b. It is important for asexual reproduction in lower organism.
c. As the daughter cells are identical to each other and to the mother cell, mitotic cell division maintains genetic stability in organisms. d. It is important for replacing the dead and damaged cells.

During interphase of mitosis, each chromosome is replicated. So, instead of having normal diploid (2n) chromosomes, the cell has tetraploid (4n) chromosomes temporarily. During Telophase, the chromosomes get divided into two groups and then cell gets equal number of chromosomes as that of mother cell.

1. It occurs in Prophase. In this phase, the chromosomes coil, shorten and become invisible.
2. It occurs in Telophase. In this phase, the chromosomes uncoil and become entangled.
3. It occurs in Metaphase. In this phase, the chromosomes are connected by the spindle fibers at their centromere.

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  • Mitosis cell division helps in ______.

    All the answers are correct
    Asexual reproduction
    Physical growth
    Regeneration and healing wounds
  • The point where two chromatin fibres attach with each other is ______.

    Centromere
    Chromatid
    Spindle fibre
    Anaphase
  • When two chromatid threads are attached with one another through centromere is ______.

    Centromere
    Chromatid
    Chromosome
    Spindle fibre
  • Prophase, Metaphase, Anaphase and Telophase fall under ______.

    Karyokinesis
    Cytokinesis
    Telophase
    both a and b
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sonika

what are the changes occured in anaphase stage of mitosis cell division


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No Name

Write down the role of mitosis in amoeba


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aasmin

differences between cytokinesis of plant and animal


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