1. Mitosis Ms. P's AP Biology 1

2. Well – what about NON eukaryotes? Ms. P's AP Biology 2 Prokaryotes undergo binary fission, which is when the daughter chromosomes move apart, and end up on opposite sides of the parent cell. The mechanism is unknown! Look on page 225 to learn about diatoms and dinoflagellates Only eukaryotes undergo mitosis, and not ALL

3. Cyclin and Cyclin-dependent Kinase (pg 226)  Kinase drives the cell cycle, but it needs to get hooked up with cyclin first.  Cyclin dependent Kinase ( Cdk ) + Cyclin = activate cell cycle VIA M-phase-promoting-factor (MPF)  Study the image on page 227 (12.14) to get a better understanding of how Cdk and the cell cycle work. Cdk + Cyclin = MPF

4. Internal and External Cues for the cell cycle  So, even though Cdks are important, scientists don’t actually know what they actually do. :(  Internal signals : A signal that delays anaphase originates at the kinetochores that are not yet attached to microtubules. All kinetochores must be attached to proceed.  External signals : Cells fail to divide if an essential nutrient is left out of the medium. Also, specific growth factors must be present.  Look at the experiment outlined on page 228 (12.15 ) to get an idea of how scientists determined that PDGF (platelet derived growth factor) is required for the division of fibroblasts in culture.  Most animal cells have Anchorage dependence, meaning the must be attached to something (inside of a culture jar or a tissue) to undergo mitosis. Kinetechore hookups, nutrients, growth factors, and anchorage dependence all regulate the cell cycle.

5. Cancer cells have escaped from cell cycle controls  Cancer occurs when cells do not stop dividing. They don’t care that growth factors are depleted – they keep going.  Watch this video on cancer and this one, which is on “Eating to starve cancer”.this video this one  Henrietta Lacks’ cells were taken – no, she wasn’t asked – for science, and that original line has been dividing and being used for cancer research. Here is a link to the synopsis and background on a book about Henrietta. I highly recommend!Here is a link  Transformation is the process by which a normal cell becomes a cancerous one.  Benign tumor – remains in the original site, and can be easily removed by surgery  Malignant tumor – becomes invasive enough to impair the functions of one or more organs. This is when you “have cancer.”  Cells may have unusual # of chromosomes  Metabolism is wonky  Completely lose attachment to neighboring cells  Metastasis – the spread of cancer cells to distant locations  If we learn more about how normal cells function, we will be better able to understand abnormal cells Cancer is the uncontrolled division of cells, which can be benign or malignant. More than one mutation must occur to produce a cancerous cell.