The Great Divide Mitosis: Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

“MITOSIS IN A NUTSHELL”

To Be Answered… THINK: How many cells are you composed of? When an organism grows bigger do you get more cells or just bigger cells or both? When do your cells divide the fastest? Slowest? Do cells ever stop dividing? Are all cells capable of division and replacement? Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

WHY DO CELLS DIVIDE? To keep a workable ratio of surface area to volume V = l x w x h SA = l x w x 6 1 cm 2cm 3 cm V = 1 cm3 V = 8 cm3 V = 27 cm3 SA = 6 cm2 SA = 24 cm2 SA = 54 cm2 Ratio = 6/1 Ratio = 24/8 Ratio = 96/64 6:1 3:1 2:1 -As cell gets larger, ratio decreases Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Why Would a Cell Divide? Solution: divide in 2! As cells absorb nutrients and get larger, the volume of the cell increases faster than the surface area This means that a cell can no longer absorb nutrients and get rid of wastes fast enough to support its demands (volume) = STARVE TO DEATH So what’s a cell to do? Solution: divide in 2! Surface area for exchange not great enough to support cell’s needs Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

When Would a Cell Divide? Growth Repair or Replacement Cancer Different cells divide at different rates: Most mammalian cells = 12-24 hours Some bacterial cells = 20-30 minutes Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Getting Older… How does cell division change over a lifetime? All cells are only allowed to complete a certain number of divisions Then they die (programmed cell death) How does cell division change over a lifetime? Childhood = cell division > cell death Adulthood = cell division = cell death The Later Years = cell division < cell death Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

The Cell Cycle INTERPHASE Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Stages of the Cell Cycle 2 stages = interphase (growth & replication of DNA) & mitotic phase (division of cell into 2 daughter cells) Cell spends about 90% of the time in interphase Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Interphase Divided into 3 phases: G1 = Growth Phase – Cells grow and develop, undergo protein synthesis and rapid growth S = Synthesis Phase - DNA replication occurs (i.e. chromosomes copied) in preparation for making new cells during mitosis G2 =Second Growth Phase = centrioles replicate, cell prepares for cell division, makes new cell parts Becomes too large = divide in 2 Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

The Mitotic Phase Equal distribution of 2 sets of chromosomes (DNA) into 2 identical daughter cells Divided into 4 stages of Mitosis: Prophase Metaphase Anaphase Telophase Cytokinesis Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Cell Cycle Tidbits How long is one cell cycle? Depends on the cell- skin cells = ~24 hours, nerve cells = never after maturity, cancer cells = very short Remember: every cell only has a certain # of divisions it can undergo, then it dies = (programmed cell death) Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Mitosis: A Closer Look Interphase Prior to entering the mitotic phase, the cell has just come out of Interphase Replicated DNA during S (synthesis) 2 complete set of chromosomes that must be distributed equally between 2 cells = mitosis Interphase Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Prophase Chromatin condenses visible chromosomes Appear as sister chromatids held together by centromere Nuclear membrane dissolves The centrioles migrate to opposite poles & spindle fibers form between them Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Duplicated Chromosome

Mitotic Appearance (Prophase) Centriole Centromere Spindle Chromosome (chromatids) Aster

Metaphase Chromosomes line-up on the metaphase plate Centromeres are attached to spindle fiber Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Anaphase Centromeres divide Spindle fibers contract Result = sister chromatids are pulled away from one another towards the poles Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Telophase The chromosomes reach the poles Nuclear membranes form around the 2 new nuclei Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Cytokinesis The cytoplam distrubted equally between the 2 new cells In animals, the cell membrane pinches together In plants, a cell plate forms from inside out Animal Plant Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Cytokinesis in plants Figure: 8.9b Caption: (b) In plants, the cytoplasm is divided by a cell plate that forms in the middle of the cell. A cell plate made up of cell-wall components gradually forms in the middle of the cell.

Cytokinesis in animals Cleavage Furrow Figure: 8.9a Caption: (a) In animals, the cytoplasm is divided by a cleavage furrow that pinches the cell in two.  A cleavage (or division) of the animal cell. The membrane pinches together forming 2 cells

ANIMAL VS. PLANT MITOSIS ANIMAL CELL Centriole and aster present Daughter cells separated by cleavage furrow PLANT CELL No visible centriole or aster Daughter cells separated by cell plate

What Mitosis Actually Looks Like Interphase Metaphase Prophase Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today Telophase Anaphase

Mitosis consists of several different phases. Figure 9.8 – Part 2 Figure 9.8 – Part 2 Mitosis consists of several different phases.

Summary of Mitosis Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

What Happens After Mitosis? The cell returns to interphase Chromosomes uncoil back into chromatin The cycle repeats itself over & over… Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

At What Stage Are Our Cells At In The Cell Cycle? Different cells can be in different stages Interphase Mitosis: Prophase Metaphase Anaphase Telophase Cytokinesis Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Can You Identify the Stages of Mitosis? Put the following mitosis stages in the correct sequence Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today

Mitosis Can you name the stages? B C D E

Identical daughter cells The Guarantee The product of mitosis is 2 cells The daughter cells are identical to each other & to the mother cell Mother cell Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today Identical daughter cells Why is this so important?

Identical daughter cells The Daughter Cells Mother cell In humans, the 2 daughter cells will have 46 chromosomes (23 pairs) 1 chromosome originally from mom & 1 from dad Each chromosome is said to have the same gene sequence Thanks to person who introduced me Explain presentation style Different, wacky, interactive Reason for madness- will be reviewed during implications May be asked to be an active participant May be asked to reinforce others Will be reinforced with candy Comments/questions welcomed throughout Reinforce me for doing well Have participants guess the number of new things they will learn today Identical daughter cells