Download - cell cycle and mitosis
Cell Cycle
Cell Cycle -life of a cell
-from its origin in the division of parent cell until its own division into two cells
Why do cells divide?
1. growth 2. renewal and3. repair
Repeating sequence of cellular growth and division throughout the life of an organism
What is cell cycle?
Interphase (90 %)
Gap 1 (G1)S (synthesis) Gap 2 (G2)
Mitotic phaseMitosisCytokinesis
Cell Cycle Stages
InterphaseThe cell prepares for division
Animal Cell DNA replicated Organelles
replicated Cell increases in
size
Plant Cell DNA replicated Organelles
replicated Cell increases in
size
Interphase
Animal Cell Plant Cell
Mitotic phase mitosis division of the nucleus happens on all somatic cells
cytokinesisdivision of the cytoplasm
Shortest part of the cycle
Mitosis has 4 subphases: prophase
metaphase anaphasetelophase
Stages of Mitotic phase
Prophase Metaphase Anaphase
TelophaseCytokinesis
Prophase• Chromatin thickens into
chromosomes
• Centriole pairs move to opposite ends of the cell
• Spindle fibers begin to form
• Nuclear membrane &nucleoli disintegrates
Prophase
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Metaphase• Chromosomes align
along the metaphase plate
• Chromosomes attached to the spindle fiber through the centromere
Metaphase
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Anaphase• Paired chromosomes
separate and move to opposite sides of the cell
• Separation of centromeres
• Separated chromosomes are called daughter chromosomes
Anaphase
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Telophase• Chromatids arrive
at opposite poles of cell
• Spindle fibers disintegrate
• Nuclear membrane reforms
• Nucleoli reappear
• Plant cells: cell plate
• Animals: cleavage furrow
Telophase
Telophase
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Cleavage furrow Cell plate
Cytokinesis
Cytoplasm divides
Produces two daughter cells, each with one nucleus
Result of Cell Cycle
two new daughter cells identical to the parent cell in
chromosome number and chromosome type
two new daughter cells will enter interphase and the cycle will continue…
THANK YOU!
Reference: revised from: http://team.zobel.dlsu.edu.ph/sites/students/H1/Lists/Announcements/Attachments/201/Cell%20Cycle.ppt.