The Cell cycle & Cell division: Mitosis How the cell in the body replicate

Cell Life Cycle  Each cell has a life cycle  The cell grows  When it gets too big it prepares to divide  When the cell divides it’s genetic material it is called Mitosis  When the cells split it is called cytokinesis

Interphase  This is the longest part of the cell’s cycle  G 1 phase – growth  S phase – DNA replication  Chromatids are formed  G 2 phase- prepare for Mitosis

Cell Division All cells come from existing cells. All living things create new cells by dividing.All cells come from existing cells. All living things create new cells by dividing. Cell division is different in prokaryotes and eukaryotes.Cell division is different in prokaryotes and eukaryotes. Prokaryotic cell reproducing

Cell Division in Prokaryotes Prokaryotes reproduce by binary fission.Prokaryotes reproduce by binary fission. Steps in prokaryote binary fission.Steps in prokaryote binary fission. –DNA replicates –Cell grows –New cell wall develops –Cell splits into two cells Binary Fission

Cell division in Eukaryotic cells  DNA the nucleus divides before the rest of the cell does.  The process of nuclear division is called mitosis.  Mitosis is a multi step process.

Mitosis  After the DNA is replicated inside the nucleus the chromosomes condense.  Then the nuclear envelope dissolves.  Chromosomes are lined up as sister chromatids in the center of the cell.

Mitosis continued  The chromatids separate into individual chromosomes  Then they are moved apart to opposite sides of the cell.

Cytokinesis  Each side of the cell has identical sets of the chromosomes  So when the cytoplasm pinches apart during cytokinesis each daughter cell will have a complete copy of the DNA

Control of cell Division The cell has checkpoints to insure cell division goes well. –G 1 checkpoint: if the cell is large and health it will divide –G 2 checkpoint: checks that the DNA was copies correctly –Mitosis checkpoint: to make sure genetic material was divided correctly.

Cancer If one of the proteins that monitors cell growth is not working properly (usually because of a mutation in the genetic code) then the cell will divide uncontrollably. This is cancer.

summary Write a one paragraph summary of the cell cycle and cell division, explain why these are important and what happens if something goes wrong.