Chapter 3: Cell Division 3.1 Cell division occurs in all organisms 3.2 Cell division is part of the cell cycle 4.3 Meiosis is a special form of cell division.

Chapter 3: Cell DivisionChapter 3: Cell Division

3.1 Cell division occurs in all organisms3.1 Cell division occurs in all organisms

3.2 Cell division is part of the cell cycle3.2 Cell division is part of the cell cycle

4.3 Meiosis is a special form of cell 4.3 Meiosis is a special form of cell divisiondivisionBefore, you learned:

-cells come from other cells through cell division-a cell must have a full set of genetic material to function-cell division enables multicellular organisms to develop, grow, and repair themselves

Now, you will learn:-about two main stages in the cell cycle-about the changes that occur in cells before mitosis-about the events that take place during mitosis

Mitosis animation/video:Mitosis animation/video: http://www.youtube.com/watch?v=AhgR

hXl7w_g Activity:Activity: http://bio.rutgers.edu/~gb101/lab2_

mitosis/index2.html

3.2 Cell division is part of 3.2 Cell division is part of the cell cyclethe cell cycle

CyclesCycles

Life cycle, Carbon cycle, Water cycleLife cycle, Carbon cycle, Water cycle Cycles: regularly repeatsCycles: regularly repeats

Cell Cycle Cell Cycle The normal sequence of development The normal sequence of development

and division of a celland division of a cell Includes:Includes:

Interphase – cell carries out its functionsInterphase – cell carries out its functions Cell division – cell dividesCell division – cell divides

Only eukaryotes undergo mitosisOnly eukaryotes undergo mitosis

InterphaseInterphase

Part of the cell cycle that the cell is NOT Part of the cell cycle that the cell is NOT dividingdividing

Cell grows to twice its original sizeCell grows to twice its original size Normal cell activities: transporting Normal cell activities: transporting

materials in and wastes out, cellular materials in and wastes out, cellular respiration (provides energy)respiration (provides energy)

Prepare for cell divisionPrepare for cell division Duplicated DNA exactlyDuplicated DNA exactly

During most of Interphase, DNA is in chromatin formDuring most of Interphase, DNA is in chromatin form

Cell Division PhaseCell Division Phase

Mitosis: nucleus dividesMitosis: nucleus divides Prokaryotes do not undergo mitosis because they Prokaryotes do not undergo mitosis because they

have only one chromosome and no nucleushave only one chromosome and no nucleus To move the DNA and other material in the parent To move the DNA and other material in the parent

cell into position for cell divisioncell into position for cell division When the cell divides, each new cell gets a full set When the cell divides, each new cell gets a full set

of DNA and other cell structuresof DNA and other cell structures Cytokinesis: division of the parent cell’s Cytokinesis: division of the parent cell’s

cytoplasm – immediately after mitosiscytoplasm – immediately after mitosis Results in two genetically identical daughter cellsResults in two genetically identical daughter cells

Cell division produces two Cell division produces two genetically identical cellsgenetically identical cells

New cells help your body to grow, New cells help your body to grow, develop, and repairdevelop, and repair

Body cells divide at different rates, Body cells divide at different rates, but the same process (mitosis) but the same process (mitosis) divides their genetic materialdivides their genetic material

MitosisMitosis

1.1. Prophase: the DNA in the nucleus Prophase: the DNA in the nucleus forms forms chromosomeschromosomes, consist of two identical , consist of two identical chromatids held together by a centromerechromatids held together by a centromere

2.2. Metaphase: Metaphase: chromosomes line up chromosomes line up in the in the middle of the cellmiddle of the cell

3.3. Anaphase: Anaphase: chromosomes/chromatids chromosomes/chromatids separate separate forming two chromosomes, which forming two chromosomes, which are pulled to opposite sides of the cellare pulled to opposite sides of the cell

4.4. Telophase: Telophase: nuclei form nuclei form around each group around each group of chromosomesof chromosomes

CytokinesisCytokinesis

Division Division of the parent cell’s of the parent cell’s cytoplasmcytoplasm

In animal cells: a fiber ring In animal cells: a fiber ring forms in the center of the forms in the center of the dividing cell, it contracts and dividing cell, it contracts and pulls the cell membrane pulls the cell membrane inwards – two daughter cellsinwards – two daughter cells

In plant cells: the cell wall In plant cells: the cell wall prevents the cell membrane prevents the cell membrane from being pulled inward. A from being pulled inward. A cell plate grows between the cell plate grows between the two new nucleitwo new nuclei

Mitosis and CytokinesisMitosis and Cytokinesis

http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter11/animations.html# Mitosis and CytokinesisMitosis and Cytokinesis

http://www.classzone.com/books/http://www.classzone.com/books/ml_science_share/vis_sim/ml_science_share/vis_sim/chm05_pg86_mitosis/chm05_pg86_mitosis/chm05_pg86_mitosis.htmlchm05_pg86_mitosis.html

3.2 Cell division is part of the 3.2 Cell division is part of the cell cyclecell cycle

Name and draw each stage of Name and draw each stage of mitosis.mitosis.