do now!! what two (2) reasons do you think cells divide?
TRANSCRIPT
Do now!!Do now!!
What two (2) reasons What two (2) reasons do you think cells do you think cells
divide?divide?
Ch. 10 Ch. 10 Cell Growth and Cell Growth and
ReproductionReproductionWhy do cells divide?Why do cells divide?
Body Growth and RepairBody Growth and Repair
• All living things growAll living things grow• All living things need to repair All living things need to repair
themselves when injuredthemselves when injured• New cells are made to make these two New cells are made to make these two
things happenthings happen• The process of making new cells is The process of making new cells is
called called
MITOSISMITOSIS
Cell CycleCell Cycle• The life of a cell is called the cell cycleThe life of a cell is called the cell cycle
• It has five main phasesIt has five main phases– GG11: this phase is for : this phase is for GGROWTH and making new ROWTH and making new
organelles.organelles.– SS phase: this phase for phase: this phase for SSYNTHESIZING YNTHESIZING
chromosomes.chromosomes.
– GG22: this phase is a second : this phase is a second GGROWTH phase ROWTH phase dedicated dedicated
to growing in size to prepare for cell division.to growing in size to prepare for cell division.– MitosisMitosis: process of cell division: process of cell division– CytokinesisCytokinesis: the end process of one cell becoming : the end process of one cell becoming
two cellstwo cells
MitosisMitosis• Done in all the body cells of living thingsDone in all the body cells of living things
• Makes a copy of original cellMakes a copy of original cell
• Done in four stepsDone in four steps–ProphaseProphase–MetaphaseMetaphase–AnaphaseAnaphase–TelophaseTelophase
ProphaseProphase1.1. Sister chromatids begin to shorten Sister chromatids begin to shorten
and thicken into chromosomesand thicken into chromosomes
2.2. Nuclear membrane begins to break Nuclear membrane begins to break downdown
3.3. Centrioles move to the poles of the Centrioles move to the poles of the cellcell
4.4. Spindle fibers form from each Spindle fibers form from each Centriole towards the center of the Centriole towards the center of the cellcell
MetaphaseMetaphase1. Centrioles are at opposite side 1. Centrioles are at opposite side
of of the cellthe cell2. Chromosomes line up in the 2. Chromosomes line up in the
middle of the cellmiddle of the cell3. Spindle fibers attach to the 3. Spindle fibers attach to the
centromere of the chromosomecentromere of the chromosome
AnaphaseAnaphase1. Chromosomes are pulled apart1. Chromosomes are pulled apart
2. Spindle fibers disintegrate after 2. Spindle fibers disintegrate after chromosome passeschromosome passes
3. Chromosomes are pulled 3. Chromosomes are pulled towards the centriolestowards the centrioles
TelophaseTelophase
1. Each side of the cell has a 1. Each side of the cell has a complete set of chromosomescomplete set of chromosomes
2. The cell starts to pinch in to split2. The cell starts to pinch in to split
3. Nucleus starts to reappear3. Nucleus starts to reappear
4.
CYTOKINESISCYTOKINESIS
•At the very end of mitosis At the very end of mitosis cytokinesis occurscytokinesis occurs
•““Cyto”- meaning cellCyto”- meaning cell
•-”kinesis” process of making -”kinesis” process of making newnew
Correctly identify the following Correctly identify the following phases of the cell cycle.phases of the cell cycle.
• Each number on the following picture Each number on the following picture represents a phase of the cell cycle represents a phase of the cell cycle
• in you do now for the week place the in you do now for the week place the correct name of the phase for each correct name of the phase for each number.number.
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