The Cell Cycle 5A How eukaryotic cells divide to make new cells.
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The Cell Cycle 5A How eukaryotic cells divide
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Transcript of The Cell Cycle 5A How eukaryotic cells divide to make new cells.
The Cell Cycle5A
How eukaryotic cells divide to
make new cells
Just like people have phases of development,
Cells have phases too.
In somatic (body) cells, a parent cell produces 2 daughter cells.
The purpose of mitosis is for growth and repair of tissue.
Three Phases or Stages
1. Interphase2. M (Mitosis) phase3.Cytokinesis
Interphase
Interphase DNA and organelles replicate
Cell spends most of its life in this stage
Stages of InterphaseG1 (growth)
S (synthesis)
G2 (growth)
G1 (growth)
• Aka First Gap• The cell grow larger• Makes proteins and
organelles
S (synthesis)
• DNA replication occurs - genetic material is duplicated so each daughter cell contains the same amount of genetic material as the parent cell
• Chromosomes duplicate to form sister chromatids
G2 (growth)
• Aka Second Gap• More growth & protein
synthesis occurs• preparing for cell division
M phase
• Aka Mitosis • Shortest of all phases• Division of the
nucleus
Mitosis
Nucleus divides Duplicated DNA is divided
into two new nuclei
Stages of Mitosis
ProphaseMetaphaseAnaphaseTelophase
Prophase
Prophase
• Nuclear membrane breaks down• Genetic material (chromosomes)
enlarges, thickens &condenses• In the cytoplasm, Centrioles
migrate to opposite ends of poles•Microtubules attach to centrioles
Prophase
Metaphase
Metaphase
• Duplicated chromosomes line up on the equator of the cell
• Spindles attach to chromosomes at the centromere & pull the sister chromatids into a line in the center of the cell
Metaphase
Anaphase
Anaphase
• Shortest phase• As the spindle contracts,
the sister chromatids separate and are pulled to opposite sides of the cell
Anaphase
Telophase
Telophase
• New nuclear membranes form to separate the genetic material
• Chromosomes shrink• Spindle breaks apart
Telophase
Mitosis
Cytokinesis
Cytokinesis
• Occurs AFTER telophase and BEFORE interphase
• Cytoplasm divides• Forms 2 new cells
Cytokinesis
http://outreach.mcb.harvard.edu/animations/cellcycle.swf
Identify the stage of the cell cycle…
Identify the stage of the cell cycle…
Identify the stage of the cell cycle…
Identify the stage of the cell cycle…
http://bio.rutgers.edu/~gb101/lab2_mitosis/index2.html
What happens when cells divide at an uncontrollable rate?
CANCER5D
Cancer is caused by the loss of cell’s ability to control division. Cancer cells divide uncontrollably.
Causes of Cancer
• Tobacco•Radiation exposure•Viral infections (HPV)•Genetics
http://www.mhhe.com/biosci/genbio/virtual_labs/BL_23/BL_23.html
