Mitosis (cell division) A sexual reproduction in and living organisms.

1. MITOSIS
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2. MITOSIS

3. MITOSIS
- -STRASBUGER- GERMAN BOTANIST- 1875-
-ROOT TIPS; SHOOT TIPS-
- HOMOTYPIC OR EQUATIONAL DIVISION

4. MITOSIS
CONTENTS
1. DEFINITION
2. OCUURANCE
3. PHASES
1. KARYOKINESIS
2. CYTOKINESIS
4. SIGNIFICANCE

5. 1. DEFINITION
THE TYPE OF CELL DIVISION THAT RESULTS IN:
- TWO DAUGHTER CELLS
- EACH HAVING THE SAME
- NUMBER AND
- KIND OF
- CHROMOSOMES
- AS THE PARENT NUCLEUS

6. 1. DEFINITION
“MITOSIS IS THAT STEP IN THE CELL CYCLE WHERE
THE NEWLY FORMED DNA IS SEPARATED AND TWO
NEW CELLS ARE FORMED WITH THE SAME NUMBER
AND KIND OF CHROMOSOMES AS THE PARENT
NUCLEUS.”
SEGREGATION AND RECOMBINATION DO NOT TAKE PLACE
DURING MITOSIS

7. MITOSIS
• MITOSIS TAKES PLACE BOTH IN SOMATIC AS WELLAS
REPRODUCTIVE CELLS.
• A CELL UNDERGOING MITOSIS IS CALLED MITOCYTE
• MITOSIS IN PLANTS IS ACENTRIC (WITHOUT CENTROMERE)
• GENERALLY, THE PROCESS OF MITOSIS IS COMPLETED
WITHIN 1–2 HOURS.
• THE STEPS OF MITOSIS ARE CONTROLLED BY DIFFERENT
GENES AND IF MITOSIS IS NOT REGULATED PROPERLY, IT
MAY RESULT IN HEALTH PROBLEMS SUCH AS CANCER.

8. MITOSIS
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9. 2. OCCURANCE
- IT IS RESPONSIBLE FOR THE GROWTH OF
TISSUES AND INDIVIDUALS.
-THE PHENOMENON OF MITOSIS IS OF UNIVERSAL
OCCURRENCE
- ITS IS FOUND IN ALL LIVING BEINGS FROM THE
SMALLEST BACTERIUM TO THE LARGEST ANIMAL

10. 2. PHASES
4- PHASES
1. KARYOKINESIS- Division of NUCLEUS
2. CYTOKINESIS- division of CYTOPLASM

11. 1. KARYOKINESIS
4- PHASES
1. PROPAHSE
2. METAPHASE
3. ANAPHASE
4. TELPHASE

12. 1. KARYOKINESIS
1. PROPAHSE (Gr. Pro- Before)
1. The first and the longest phase.
2. Chromosomes become visible as:
- Short - Thick
- Helically coiled
- Threads

13. 1. KARYOKINESIS
1. PROPAHSE (Gr. Pro- Before)

14. 1. KARYOKINESIS
1. PROPAHSE
3. EACH CHROMOSOME SPLITS INTO TWO
CHROMATIDS JOINED AT THE CENTROMERE.
4. NUCLEAR MEMBRANE STARTS DISSOLVING.
5. NUCLEOLUS STARTS DISSOLVING AND
DISAPPEARING.

15. 1. KARYOKINESIS
1. PROPAHSE

16. MITOTIC SPINDLE
Mitotic spindles are:
- microtubule-based structures
- that separate chromosomes
- during mitosis.

17. SPINDLE
FORMATION
- MICROTUBULES
- MADE OF TUBULIN: Contractile Protein

18. SPINDLE
- SPIDLE FIBERS-
1. KINETOCHORE MICROTUBULES: -
Attached to the chromosomal kinetochore
2. PRO-MICROTUBULES: - Interact with
microtubules with opposite poles of cell

19. SPINDLE
- KINETOCHORE-
- CEN SEQUENCE: Specialized DNA sequence
located at the centromere
- It binds with specialized protein to form a protein –
DNA Complex- Kinetochore

20. SPINDLE
- KINETOCHORE-

21. 1. KARYOKINESIS
2. METAPHASE (Gr. Meta- Between)
1. Nuclear membrane disintegrates and disappears
completely
2. Nucleolus disintegrates and disappears completely
3. Spindle fibers start appearing . These fibers get attached
to chromosomes at centromeres
4. Chromosomes become shorter and thicker

22. 1. KARYOKINESIS
2. METAPHASE
5. CHROMOSOMES ARRANGE THEMSELVES IN THE
CENTRE - ON THE EQUATOR OF SPINDLE.
6. AT THE END OF METAPHASE, TWO CHROMATIDS
OF EACH CHROMOSOME ALSO START
SEPARATING.

23. 1. KARYOKINESIS
2. METAPHASE

24. 1. KARYOKINESIS
3. ANAPHASE (Gr. Ana- Back)
1. Chromatids separate from each other at centromere and called
daughter chromosomes
2. Daughter chromosomes move to the opposite poles of the spindle
3. Daughter chromosomes appear ‘V’, ‘U’ or J-shaped during their
movement towards poles

25. 1. KARYOKINESIS
3. ANAPHASE

26. 1. KARYOKINESIS
4. TELOPHASE (Gr. Tel- End)
1. Daughter chromosomes are now at the end of the
spindle, i.e., present on two opposite poles
2. Nuclear membrane reforms around each group of
daughter chromosomes
3. Nucleolus reforms

27. 1. KARYOKINESIS
4. TELOPHASE (Gr. Tel- End)
4. Two nuclei are organised, one at each pole of the parent
cell
5. Chromosomes begin to loose their compact structure
6. Spindle fibers disappear gradually
7. Thus formed two daughter nuclei are exactly similar to
the parent nucleus.

28. 1. KARYOKINESIS
4. TELOPHASE

29. 2. CYTOKINESIS

30. 2. CYTOKINESIS

31. 2. CYTOKINESIS

32. 2. CYTOKINESIS

33. 2. CYTOKINESIS

34. SIGNIFICANCE
1. Mitosis results in the formation of two daughter
cells identical with that of the parental cell.
2. DNA, the main component of chromosomes, is
distributed equally among the two newly formed
nuclei.

35. SIGNIFICANCE
3. Both the daughter cells formed after mitosis are identical
and have the same genetic constitution, qualitatively as well
as quantitatively, as the parent cell.
4. The number of chromosomes remains the same from one
generation to another generation.

36. SIGNIFICANCE
5. Resulted daughter cells have the same characters as were
present in the parent cell.
6. The characters of the plants grown by vegetative
reproduction may be preserved for a long period.

37. MITOTIC POISON
• CHEMICALS THAT CAUSE ANOMALIES IN CELL DIVISION
ARE KNOWN AS MITOTIC POISON.
• THESE CHEMICALS INTERFERE WITH SPINDLES
• THESE CHEMICALS PRODUCE NONDISJUNCTION.
• COLCHICINE AND VINCRISTINE INHIBIT MICROTUBULES
ASSEMBLY

38. CARBOHYDRATES
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39. CARBOHYDRATES
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