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.