Cell Cycle & Cell Division

What is the cell theory Cell is the basic structure of all living things. All organisms are made of cells. All cells come from pre-existing cells.

Cell Cycle- Pattern of Growth What’s happening Gap 1 Growth Synthesis DNA Replicates Gap 2 Cell Preparing to Divide Mitosis Cell Divides http://www.nobel.se/medicine/laureates/2001/press.html

Knowledge Check Why does the cell cycle only apply to eukaryotic cells? Because prokaryotic cells does not contain a nucleus or membrane bound organelles. According to the graph do all cells grow within the same amount of time? No. Cells grow based on needs. The more the body needs those types of cells the faster they will divide. (pg.136).

Chromosomes Chromosome- Long thread of DNA Human body has 46 chromosomes Before a cell divides, it looks like long strands of spaghetti.

Chromosomes Histones- Protein that helps condense (pack) the DNA strands. Chromatin- Combination of DNA and protein

Chromosomes Chromatid- half of a duplicated chromosome (X-shape). Sister chromatids- identical chromatids

Chromosomes Centromere- Hold chromatids together Telomeres- At the ends of chromosome Prevent chromosomes from attaching to each other.

Also known as the Growth Phase INTERPHASE Also known as the Growth Phase

Interphase This is the stage before mitosis Cell is preparing to divide. Organelles and DNA duplicates At the end, the cell will have two full sets of DNA or chromosomes

MITOSIS

Mitosis Results in the creation of two identical daughter cells. Each identical to original parent cell Important for growth and repairing damaged cells.

Stages of Mitosis (PMAT) Prophase Metaphase Anaphase Telophase & Cytokinesis

Prophase Nucleus prepares for division by beginning to break apart. This allows chromosomes to become free floating in the cytoplasm. All Chromosomes copies are held together at the centromere to create an X formation Spindle fibers grow

Metaphase Chromosome line up in the center of the cell. Spindle fibers attach to chromosomes at the centromere (where they are joined).

Anaphase Spindle fibers begin to separate chromosome One complete set is pulled to one side and the other complete set is pulled to the other side of the cell. This ensures each cell has the exact same genetic material.

Telophase Cytoplasm pinches in at the center of the cell 2 nuclear membrane re-form around the chromosomes Chromosomes began to uncoil 2 Daughter cells are identical to parent cell.

Cytokinesis Each daughter cell ends up with the same number of identical chromosomes The cells will also have half the organelles and cytoplasm.

Mitosis Animation http://www.cellsalive.com/mitosis.htm

Cell Division in Cancer Cells

Cancer Cells Comes from normal cells that have suffered damaged or mutations to their genes. Uncontrolled cell division Divide more than healthy cells Clump together forming tumors They do not perform the functions of healthy cells so they are growing and growing but doing nothing.

Cancer Cells Amoeba sisters cell cycle and cancer cells Cancer cells dividing video https://www.youtube.com/watch?v=IeUANxFVXKc Amoeba sisters cell cycle and cancer cells https://www.youtube.com/watch?v=lpAa4TWjHQ4