The Cell CycleThe Cell Cycle
Cell Theory: all cells come from pre-Cell Theory: all cells come from pre-existing cellsexisting cells
Prokaryotes: Divide by binary fissionProkaryotes: Divide by binary fissionEukaryotes: Divide by mitosis or meiosisEukaryotes: Divide by mitosis or meiosis
Mitosis: Replication of somatic cells (body Mitosis: Replication of somatic cells (body cells)cells)
Meiosis: Division of germ cells (sex cells)Meiosis: Division of germ cells (sex cells)
The Cell CycleThe Cell Cycle
InterphaseInterphaseNormal cell functions and preparation for Normal cell functions and preparation for
division division MitosisMitosis
Separation of chromosomesSeparation of chromosomesCytokinesisCytokinesis
Division of cytoplasm and cell membraneDivision of cytoplasm and cell membrane
GG11: First Growth Phase: First Growth Phase
G stands for GapG stands for GapNormal cell function such as metabolism, Normal cell function such as metabolism,
protein synthesis, and growthprotein synthesis, and growthTypically represents the majority of cell Typically represents the majority of cell
cyclecycleChromosomes are Chromosomes are not replicatednot replicatedGG00: resting phase, no growth or division.: resting phase, no growth or division.
S: Synthesis PhaseS: Synthesis Phase
Relatively short period of timeRelatively short period of timeDNA chromosomes are replicated within DNA chromosomes are replicated within
the nucleusthe nucleusChromosomes are uncondensed and not Chromosomes are uncondensed and not
clearly visibleclearly visibleReplicated pairs of chromosomes are Replicated pairs of chromosomes are
connected at DNA region called connected at DNA region called centromerecentromere
Sister Sister ChromatidsChromatids
Two identical DNA Two identical DNA moleculesmolecules
Attached together at Attached together at the DNA sequence the DNA sequence called centromerecalled centromere
G2: Second Growth PhaseG2: Second Growth Phase
G stands for GapG stands for GapNormal cell function and cell growth Normal cell function and cell growth
continuecontinueOrganelles replicate in final preparation to Organelles replicate in final preparation to
cell divisioncell division
MitosisMitosis
Division of cell nucleus into two nucleiDivision of cell nucleus into two nuclei4 phases4 phases
ProphaseProphaseMetaphaseMetaphaseAnaphaseAnaphaseTelophaseTelophase
ProphaseProphase Chromatin condenses Chromatin condenses
into well defined into well defined chromosomeschromosomes
Nuclear envelope Nuclear envelope dissolvesdissolves
Replicated centrioles Replicated centrioles separate across cellseparate across cell
Spindle apparatus formsSpindle apparatus forms
Spindle ApparatusSpindle ApparatusMicrotubules generated from centriole Microtubules generated from centriole
pair extend across cell and attach to pair extend across cell and attach to proteins at chromatid centrosomeproteins at chromatid centrosome
MetaphaseMetaphase
Chromatids are pulled Chromatids are pulled between centrosomesbetween centrosomes
Aligned across Aligned across equator of cellequator of cell
Midline of cell is Midline of cell is called metaphase called metaphase plateplate
AnaphaseAnaphase
Microtubules attached Microtubules attached to chromatids shortento chromatids shorten
Chromatids are pulled Chromatids are pulled apartapart
Chromosomes Chromosomes separate to poles of separate to poles of cellcell
TelophaseTelophase
Non-kinetochore Non-kinetochore microtubules continue microtubules continue to length to length
Nuclear envelope Nuclear envelope reforms at each polereforms at each pole
Chromosomes unfold Chromosomes unfold back to chromatinback to chromatin
CytokinesisCytokinesis
Cytoplasm is divided Cytoplasm is divided between two new cellsbetween two new cells
In animal cells plasma In animal cells plasma membrane pinches membrane pinches closeclose
In plant cells cell wall is In plant cells cell wall is constructed between constructed between nucleinuclei
CancerCancer
When cells lose control When cells lose control of the cell cycle they of the cell cycle they become cancerousbecome cancerous
A tumor is a mass of A tumor is a mass of cells that cannot stop cells that cannot stop dividingdividing
Can occur in any organ Can occur in any organ or tissueor tissue
Top Related