Cell cycle and check points
- 1. CellCycleinYeastandCellularCheckPoints SUBMITTED BY : A.MOHAMED MANSURALI ROLL.NO:19PA7763 I-M.Sc (BOTANY)
- 2. YEAST USED TO STUDY CELL CYCLE : Saccharomyces cerevisiae(Budding Yeast) Unusually short G2 Phase. Model for Cellbiology problems.
- 3. Cell Cycle: The life of a cell from its formation to its division into two off-spiring is known as cell cycle. There are two periods are present in the life of a cell. They are, 1)Inter phase 2)mitotic phase (M-phase) The inter phase alternate with mitotic phase.
- 5. 1) Inter phase: It Is A Resting Phase. In This Phase Cell Grows , Increase In Volume. Synthesize RNA,DNA And Proteins. It consists of - 1) G1-phase: i. The first gap phase or first growth phase ii. Pre DNA-synthesis phase 2) S-phase: i. It is the Synthetic phase ii. DNA- synthesis phase 3)G2-phase: i. The second gap or growth phase ii. Synthesis RNA and proteins iii. Post DNA Synthesis phase
- 6. 2)MITOTIC PHASE (M-PHASE): M-Phase is the division phase. During this phase the cells divides into two daughter cells. Two sub-phases: 1)Karyokinesis : -division of nucleus into two daugter cells. 2)Cytockinesis: -division of cytoplasm into two daughter cells.
- 7. 1)Karyokinesis: division nucleus into two daugter cells. It consists 4 stages namely, 1)prophase 2)metaphase 3)anaphase 4)telophase
- 8. 1)Prophase: • First stage of mitosis. • Cell became spheroid and viscous. • Chromosomes become shortend and thickend. • Each chromosome form two chromatids. Two chromatids are connected with the centromere. • Nucleolus starts to disappear. • RNA content of chromosomes is increased.
- 9. 2.METAPHASE: Also Known As Spindle Assembly Checkpoint. Each Spindle Fibre Is Formed Of 4-10 Microtubles. They Are Formed Of A Protein By Tubulin. The centromere of each chromosome divides into two, each being associated with a chromatid.
- 10. 3.ANAPHASE: Chromatids of each chromosome are separeted and form two chromosomes called daughter chromosomes. They move towards the opposite poles of the cell.
- 11. 4.TELOPHASE: Final stage of karyokinesis. Chromes at the poles begin to uncoil and lengthen. New nucler membrane develops around the chromosomes by endoplasmic reticulum. Spindle fibres breakdown and disappear. Two daughter nuclei formed and they attain the appearnce of the interphase nuclei.
- 12. 2.CYTOKINESIS: Cytoplasm Into Two Daughter Cells. After the karyokinesis a cell plate develops between the two daughter nuclei.many small vesicles are developed by the Golgi complex and endoplasmic reticulim,they called as phragmoplast. They fuse together to form a disc like structure cell plate. it is made up of cellulose and pectic substances. The cell plate grows and fuse with the lateral wall of the cell. The cell wall became thickend at finally it will be separeted.
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