CELL CYCLE BY NURJULAIHA ROSLAN CELL CYCLE Sequence

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CELL CYCLE BY NURJULAIHA ROSLAN

CELL CYCLE BY NURJULAIHA ROSLAN

CELL CYCLE � Sequence of stages between cell division and the next. � Time

CELL CYCLE � Sequence of stages between cell division and the next. � Time taken to complete one cell cycle varies with tissues and among spesis. � Enviromental factor such as changes in temperature and p. H and declining nutrients levels lead to declining cell division rates.

Cells cycle involve 3 continuous stages-Interphase -Mitosis -Cytokinesis

Cells cycle involve 3 continuous stages-Interphase -Mitosis -Cytokinesis

INTERPHASE � Phase between mitotic division and appears to be resting phase. � Can

INTERPHASE � Phase between mitotic division and appears to be resting phase. � Can be divived to 3 phase v G 1 phase v S phase v G 2 phase

G 1 PHASE � RNA and protein produced. � Cells grows rapidly. � Chromosomes

G 1 PHASE � RNA and protein produced. � Cells grows rapidly. � Chromosomes not yet visible. � Organelle grows and increase in size. � Nucleolus clearly visible.

S PHASE � DNA replicates. � Synthesis of Histone proteins. � Chromosomes have 2

S PHASE � DNA replicates. � Synthesis of Histone proteins. � Chromosomes have 2 chromatids. � Chromosomes not visible.

G 2 PHASE � Cells increase in mass. � More Mitochondria and Chloroplast. �

G 2 PHASE � Cells increase in mass. � More Mitochondria and Chloroplast. � Energy store increase. � Chromosome start shorten and condense. � Replication of Centrioles

mitosis MITOSIS � Process of dividing a cell by replication and dividing the original

mitosis MITOSIS � Process of dividing a cell by replication and dividing the original chromosomes to obtain 2 new cells identical to one another. � Divided into 4 stages v Prophase v Metaphase v Anaphase v Telophase

PROPHASE � Chromatin in nucleus begins to condense. � Nucleolus disappear. � Mitotic Spindle

PROPHASE � Chromatin in nucleus begins to condense. � Nucleolus disappear. � Mitotic Spindle begin to form. � Centrosomes formed and move apart, push by microtubules. � Chromosomes migrate to centre of nucleus. � Disappearance of nuclear envelope.

METAPHASE � Nuclear envelope breaks up completely. � Centrioles have reaches opposite poles. �

METAPHASE � Nuclear envelope breaks up completely. � Centrioles have reaches opposite poles. � Attaches to Spindle Fibre in the Centromere. � Chromosomes line up on metaphase plate.

ANAPHASE � Centromere divide and 2 chromatids of each chromosomes seperates. � Spindle Fibre

ANAPHASE � Centromere divide and 2 chromatids of each chromosomes seperates. � Spindle Fibre pull the sister chromatids appart towards opposite pole of cells. � Each poles contain a complete set of chromosomes.

TELOPHASE � Spindle fibre disappear and centrioles divide into two. � Chromosomes uncoil and

TELOPHASE � Spindle fibre disappear and centrioles divide into two. � Chromosomes uncoil and return to chromatin form. � Nuclear envelope reform. � Nuclei begin to form.

CYTOKINESIS � Splitting the cytoplasm that seperates daughters nuclei into two individual daughter cells.

CYTOKINESIS � Splitting the cytoplasm that seperates daughters nuclei into two individual daughter cells. � Furrow forms then it will slowly reduces the diameter of cell until it eventually slices all the way into center of the cell. � Cells seperates completely and 2 complete cell form.

SIGNIFICANCE OF CELL DIVISION � For cell replacement � For growth � To maintain

SIGNIFICANCE OF CELL DIVISION � For cell replacement � For growth � To maintain the genetic stability � Reproductive development of organism � Continual of life or survival of all organisms.

WATCH THIS VIDEO!!! � For more understanding , watch this video through this link.

WATCH THIS VIDEO!!! � For more understanding , watch this video through this link. . � You. Tube - Mitosis. flv or � http: //www. youtube. com/watch? v=ATl. Uv. AGh. EU