2. Which of the following statements best describes the relationships among possible environmental influences, the p53 gene, and cancer? * A. Environmental influences can lead to mutations in the p53 gene, which can cause certain cancers. B. Increased levels of p53 protein, rather than environmental influences, can cause certain cancers. C. Mutations in the p53 gene increase environmental influences that can cause certain cancers. D. Genes such as p53 are less causal than environmental influences in stimulating certain cancers.

7. THE IMMUNE SYSTEM: Take a sheet of paper and copy this chart except for the bottom 3 boxes. SKIN, MUCOUS WBC, PROTEINS

13. T CELLS T CELLS P HAGOCYTES CAPTURE A FOREIGN INVADER AND PRESENT IT TO A T CELL (APC) THIS ACTIVATES T CELL P HAGOCYTES CAPTURE A FOREIGN INVADER AND PRESENT IT TO A T CELL (APC) THIS ACTIVATES T CELL T CELLS BIND TO AND DESTROY INFECTED BODY CELLS T CELLS BIND TO AND DESTROY INFECTED BODY CELLS T CELLS ALSO KILL CANCER CELLS T CELLS ALSO KILL CANCER CELLS HUMORAL B CELLS B CELLS A PATHOGEN BINDS TO B CELL, THE PATHOGEN IS ENGULFED AND ITS ANTIGENS ARE DISPLAYED ON THE CELL A PATHOGEN BINDS TO B CELL, THE PATHOGEN IS ENGULFED AND ITS ANTIGENS ARE DISPLAYED ON THE CELL A T CELL ENCOUNTERS THIS APC AND ACTIVATES IT A T CELL ENCOUNTERS THIS APC AND ACTIVATES IT T HE B CELL THEN MAKES ANTIBODIES AGAINST THE PATHOGEN T HE B CELL THEN MAKES ANTIBODIES AGAINST THE PATHOGEN