Which of the following investigators was (were) responsible for the discovery that in DNA from any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine?

#Question id: 1501

#Unit 4. Cell Communication and Cell Signaling

When a culture of rodent cells is infected with a DNA tumor virus whose gene products bind to p53 and RB, all the cells take on characteristics of malignancy. If the viral gene coding the p53-binding protein is mutated, but that coding for the RB-binding protein is not mutated, how will infected cells respond?

#Question id: 1502

#Unit 4. Cell Communication and Cell Signaling

The textbook states that cells of patients with adenomatous polyposis coli (APC) “contain a deletion of a small portion of chromosome #5, which was subsequently identified as the site of a tumor-suppressor gene called APC.” In which cells of these patients would you expect to find this chromosomal deletion?

#Question id: 1503

#Unit 4. Cell Communication and Cell Signaling

When the genes responsible for familial breast cancer were sequenced, it was found that the polypeptides they encoded contained a zinc finger motif. What does this suggest to you about the normal functions of the products of these genes?

#Question id: 1504

#Unit 4. Cell Communication and Cell Signaling

Tumor-suppressor genes usually act as .......... genes, and oncogenes usually act as ...........  genes.

#Question id: 1505

#Unit 4. Cell Communication and Cell Signaling

Which of the following types of genes have not been identified as oncogenes?

#Question id: 1506

#Unit 4. Cell Communication and Cell Signaling

An oncogene codes for a growth factor receptor that is constitutively active. Of the following statements about a culture of cells expressing this gene, which would you expect to be true?