Article-2⃣9⃣
*Self-practice*
10 th -Science Part 2
Topic 2: *Life Process in Living organisms Part-1*
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*Today's exercise*
1) Describe mitosis in detail with the help of diagrams.
2) Click on the link given below to see the video.
https://youtu.be/c5hA0WCv1lg ================
*Mitosis*
Continuing ...
3) *Anaphase*
Spindle fibers are attached to the chromosome. These spindle fibres begin to shrunk and pull the sister chromatids towards the poles. This causes slight increase in the cell size near the poles.
4) *Telophase*
◆ *Chromosome seggregation*: - Chromosomes that reach both the poles of the cell come together.
◆ *nuclear membrane formation:* - Nuclear membrane is formed surrounding both the sets of chromosomes. As a result, two identical nuclei are formed in a single cell.
◆ *Unfolding:* - Unfolding or de- condensation of chromosomes takes place and are transformed into DNA thread again.
◆ *Spindle fiber disappears* and nucleoli appear in both nuclei.
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B] *Cytokinesis*
◆ *Starts:* - Cell division begins after the end of telophase.
◆ *Contraction:* - The cell membrane in the center of the cell begins to contract.
◆ *Notch formation:* - A parallel notch is formed at the equatorial surface of the cell and it gradually deepens.
◆ *Completeness:* - The notching completes and two new daughter cells are formed.
◆ *Exception:* - In plant cells, instead of a notch, a cell plate is formed and the cytokinesis takes place.
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*Advantages of mitosis*
Mitosis is required for the following reasons:
◆ *Growth* - For body growth
◆ *Repair* to make up for the wear and tear of the body caused by aging of cells.
◆ To heal the *wounds*
◆ For the formation of *blood cells*
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■ Trick to remember the four stages of mitosis.
Remember word *I, PMAT*
It means "I Pee on MAT"
'I' means Interphase, P = Prophase, M = Metaphase, A = Anaphase and T = Telophase.
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*Question-1*
Why the pair of chromosomes given the feminine name "Sister Chromatid" and the progenitor cell as "Daughter Cell"?
*Answer* -
The cell that divides is called 'mother cell'. However, after cell division, the mother cell is transformed into two newborn cells. These genital cells also have the ability to divide (reproduce) so they are called 'daughter cells'. In human culture, woman is considered as a symbol of fertility. Therefore, mother cells, daughter cells and sister chromatids may have been named so.
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★ *Click on the link below to get all the previous articles.*
https://shrishail-mathapati.blogspot.com/
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