Cracking the Code of Life Section 10.3 Mutations Cracking the Code of Life

Cancer: Breakdown of the cell Cycle CELLS NEED TO REPRODUCE: Human Body made up of trillions of cells – most cells make new cells to: replace old/damaged cells replace dead cells maintain homeostasis grow

2. Cells undergo growth and division - this cycle is governed by the cell cycle clock Interphase Cell Division: Mitosis and Cytokinesis

3. Events which can disrupt cell cycle : (Causes of cancer) Exposure to harmful chemicals Food additives &preservative Drugs/Alcohol Household products (cleaners) Radiation UV from the sun Xrays Viruses – ex. HPV Aging

4. Disruption in the cell cycle can lead to cells not dividing, cannot maintain homeostasis, rupture and die cells dividing uncontrollably = mass of cells called TUMOR benign – harmless tumors malignant – harmful tumors

5. How cancer spreads-what cells need Food, Water, Oxygen Dispose of waste blood delivers wanted materials while removing unwanted materials Cells require adequate blood supply Tumors will not be able to grow larger than a grain of rice unless they have an adequate blood supply and so (must encourage blood vessels to grow).

ANGIOGENESIS: tumors secrete chemicals which cause blood vessels to grow to them & supply w/ materials needed to continue growing

METASTASIS: Cells break away from original tumor, enter blood supply and travel to other parts of body. Cells Must: break away from primary tumor invade surrounding tissue entering blood or lymph vessels stop in capillaries of distant organs gain access to neighboring tissues @ new site & begin to grow

Mutation Situations Adult body cell  only cells affected are ones that result from mitosis Example: Embryonic Cell  only cells affected are ones from forming from those cells Sex Cells all cells in offspring could be affected

Gene Mutations Frameshift: Point: substitution of a nucleotide Deletion: nucleotide is removed completely Ex: Duchenne muscular dystrophy Insertions: extra nucleotide is added Ex: Huntington's disease Point: substitution of a nucleotide Ex: sickle-cell anaemia

Health and Sickle Red Blood Cells

Section 10.4 Cell Differentiation

How do cells become specialized for different functions? Stem Cell: immature cell with no specific function Differentiation: cell matures into adult cell with a specific job

What is totipotent?