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

http://www.google.com/url?sa=i&source=images&cd=&cad=rja&docid=QX713yvq_EliAM&tbnid=lZJRBtfnaE96PM:&ved=0CAgQjRwwAA&url=http://www.ivy-rose.co.uk/HumanBody/Cells/Cell-Division_Mitosis-Diagram.php&ei=qqhEUtbSH8Oh2gWo24GYCg&psig=AFQjCNHaaWwPwQUk0sN39iJ6ISiI7keM9Q&ust=1380317738602558

M phase

• Aka Mitosis • Shortest of all phases• Division of the

nucleus

Mitosis

Nucleus divides Duplicated DNA is divided

into two new nuclei

Mitosis Animation

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 Animation

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