http://www.johnkyrk.com/mitosis.html

InterphaseMitosis

Scientists have identified a repeating cycle of events in the life of a cell

This cycle of events is called the cell cycle

Every hour, about one billion (109) cells die and one billion cells are made in your body. Part of the cell cycle includes making new cells in a process called cell division.

The cell cycle has four phases: G1 Phase S Phase G2 Phase M PhaseInterphase

The cell spends about 90% of its time in interphase

Composed of 3 phases: G1, S, G2

Often called the “resting” phase but cell is not at rest

Cell is not dividing Cell is active:

taking in nutrients Growing conducting other

normal cell functions

http://student.ccbcmd.edu/~gkaiser/biotutorials/dna/mitosis/images/interphase1_pc.jpg

Chromosomes are stored in the nucleus

Genetic information is stored on chromosomes

The coded information on chromosomes is called DNA (deoxyribonucleic acid)

Chromosomes are long pieces of coiled DNA and proteins

When the cell is not dividing, chromosomes are unwound and not visible

DNA and proteins are spread throughout the nucleus

This unwound form of chromosomes is called chromatin

At the beginning

of cell division, chromosomes condense into visible structures

Chromosomes are only visible when the cell is dividing

Chromosomes that have duplicated will have two sister chromatids attached to the same centromere

Sister chromatids have identical genetic information

Chromosomes duplicate during S phase

Why do chromosomes duplicate?

Period of rapid growth

New proteins and organelles are produced

Chromosomes are unwound (chromatin)

Preparing for DNA synthesis (S phase)

Cell leaves cell cycle

Can be temporary or permanent

But not necessarily dead

Example: neurons

Where a cell checks to make sure it is able to continue to the next phase

Cell size must be large enough

Environment must be suitable

Before cell division can occur, each chromosome is copied

Results in an entire identical copy of chromosomes

When cells divide, each set of chromosomes will end up in each new cells

1. Use candies to create 2 structures that represent chromosome in S phase

2. Ask teacher to check your structure

Cell grows larger in size in preparation for cell division

Produces organelles and structures needed for cell division

Example: centrioles and nucleolus are duplicated

http://biology.uoregon.edu/reference/ort_mitosis/images/I-image1-label.jpg

Shortest part of interphase

DNA is replicated Cell size must be

large enough Environment

must be suitable

http://highered.mcgraw-hill.com/sites/9834092339/student_view0/chapter10/animation_-_cell_division.html(2nd half)

Once the cell is ready to divide and make two new identical cells, it enters M Phase

During the M Phase, all of the cell’s energy is devoted to the process of cell division

M phase is divided into mitosis and cytokinesis

PMAT

ProphaseMetaphaseAnaphaseTelophase

Chromosomes condense (no longer chromatin) and become visible

Nuclear envelope disappears

Centrioles move to the poles of the cell

Spindle fibers begin to extend from the poles

Image is showing:Chromosomes

condensing Nuclear envelope

disappearing

http://student.ccbcmd.edu/~gkaiser/biotutorials/dna/mitosis/images/early_late_prophase1_pc.jpg

Illustration is showing:

Nuclear envelope disappearing

Centrioles moving to poles

Spindle fibers forming

1. Use candies to create 2 structures that represent chromosome in S phase

2. Ask teacher to check your structure3. Use additional candy to create structure for prophase4. Ask teacher to check your structure

Chromosomes line up along equator (center of the cell)

Spindle fibers attach to the centromeres of each chromosome

http://images.wellcome.ac.uk/indexplus/result.html?_IXMAXHITS_=1&_IXACTION_=query&_IXFIRST_=16&_IXemailreal=true&_IXbox=259047&_IXSPFX_=templates%2Ft&_IXFPFX_=templates%2Ft

1. Use candies to create 2 structures that represent chromosome in S phase

2. Ask teacher to check your structure3. Use additional candy to create structure for prophase4. Ask teacher to check your structure5. Create metaphase structure by making changes to your

prophase structure6. Ask teacher to check your structure

Spindle fibres shorten pulling the chromosomes to opposite poles

Sister chromatids separate at the centromere and move to the poles

Image is showing:

Chromosomes moving to the poles

1. Use candies to create 2 structures that represent chromosome in S phase

2. Ask teacher to check your structure3. Use additional candy to create structure for prophase4. Ask teacher to check your structure5. Create metaphase structure by making changes to your

prophase structure6. Ask teacher to check your structure7. Create anaphase structure by making changes to your

metaphase structure8. Ask teacher to check your structure

Chromosomes uncoil and become invisible

Nuclear envelope reappears

Spindle fibers disappear

Image is showing:

Chromosomes uncoiling

Nuclear envelope reforming

Occurs simultaneously with cytokinesisDaughter cells have identical genetic information

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_the_cell_cycle_works.html

-chromosome condense (coiled, visible)-nuclear membrane disappear-centrioles move to poles-spindle fiber form

-chromosome line up along equator-spindle fibers attach to centromere of chromosome

-Spindle fiber shorten & pulling chromosomes-centromere divide-each sister chromatid move to opposite poles

-chromosomes uncoil to chromatin-nuclear membrane reform-spindle fiber disappear-daughter cells have identical genetic information

Separation of the cell and cell contents Cytoplasm Organelles Cell membrane

Does not have to be an equal division

Daughter cell contents can be different

Pinching the cell membrane forming a furrow

http://www.uic.edu/classes/bios/bios100/lectf03am/cleavage.jpg

Fluorescence Microscopy

http://micro.magnet.fsu.edu/cells/fluorescencemitosis/cytokinesis2large.html

Green: microtubules Blue: chromosomesOrange: mitochondria

Formation of a cell plate

Formation of a cell plate

http://student.ccbcmd.edu/~gkaiser/biotutorials/dna/mitosis/images/telophase3_pc.jpg http://www.bio.txstate.edu/~dlemke/botany/1410lab/lab_exercises/lab3/cell_cycle/cytokinesis.jpg

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__mitosis_and_cytokinesis.html

Two daughter cells each containing identical genetic information

Daughter cells have the same number of chromosomes as the original parent cell

For each diagram:

Identify the stage of mitosis

Name one characteristic that helped you identify the stage

http://home.comcast.net/~mjmayhew42/Reading%20Guides/Chapter%2010_files/image004.jpg

Green: microtubules (spindle fibres and cytoskeleton) Blue: chromosomes Orange: mitochondria

http://preuniversity.grkraj.org/html/2_CELL_DIVISION_files/image009.jpg

http://www.blackspvbiology.50megs.com/Images2/OnionRootTipMitosis.jpg