ppt of The Cell Cycle and apoptosis practical

Cell cycle: is a set of events responsible for cell duplication
It is subdivided into four phases, G1, S, G2, and M.
G1 - primary growth phase
S – synthesis; DNA replicated
G2 - secondary growth phase
M - mitosis
Interphase - G1 Stage (gap one phase)
?1st growth stage after cell division
?Cells mature by making more cytoplasm & organelles
?the cell grows and proteins are synthesized, restoring the daughter cells to normal volume and size.
Interphase – G2 Stage
?2nd Growth Stage
?Occurs after DNA has been copied
Mitosis
•The cell prepares to divide: the centrioles grow to maturity; energy required for the completion of mitosis is stored; and RNA and proteins necessary for mitosis are synthesized, including tubulin for the spindle apparatus.
•lasts 1 to 3 hours.
•It follows the G2 phase and completes the cell cycle.
•Division of the nucleus (karyokinesis) and cytoplasm (cytokinesis) results in the production of two identical daughter cells.
•It consists of four major stages.
1- Prophase :
•begins when the chromosomes condense, the nucleolus and nuclear envelope begin to disappear.
•The centrosome (contains centrioles) migrate to opposite poles of the cell, and from them spindle fibers are forms.
•Chromosomes consist of two parallel sister chromatids attached at the centromere
• Kinetochores develop at the centromere region