7. The p53 protein is involved in DNA repair and in triggering cell death when repair is not possible. Why
are some cancers associated with defective p53 genes?

A. Because in cells with damaged p53 protein levels rise and cause apoptosis

B. Because cells with damaged p53 proteins are not triggered to die and will grow and divide
uncontrollably

C. Because repair and cell death do not depend on the p53 protein

D. Because cells with damaged
DNA do not grow
8. Stewart is investigating the responses of plants to their environment. As part of the investigation, he
studies a plant that receives sufficient water and has straight, upright stems and firm leaves. He also
studies another plant that was grown in dry soil, and that has wilted stems and leaves.
When Stewart examines the cells of the plants under a microscope, which organelle will display the
greatest difference between the two plants?