1.
In multicellular organisms, nondividing cells stay in G1 phase. For the cell, why is it advantageous to be held in G1 phase rather than S, G2 , or M phase?
To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.
2.
The Rb protein helps regulate the cell cycle in many types of cells. Children with hereditary retinoblastoma have a defective version of the Rb protein, but get tumors only in their eyes—not elsewhere. Suggest a hypothesis to explain why tumors start only in the retinas of children. How could you test your hypothesis?
To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.
3.
Predict the outcome of an experiment involving fusion of a cell in G1 phase with a cell in G2 phase. What would happen to the G1 –phase nucleus? To the G2 -phase nucleus? Why?
To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.
4.
Cancer is primarily a disease of older people. Further, a group of individuals may share a genetic predisposition to developing certain types of cancer, yet vary a great deal in time of onset—or not get the disease at all. Discuss these observations in light of the claim made in this chapter that several defects usually have to occur for cancer to develop.
To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.
