An example of coordinate control is the down-regulation of ribosomal RNA synthesis in response to amino acid starvation, which will cause synthesis of ribosomal proteins to be limited.  What is the correct order of the following events that participate in the signaling process?

1. Binding of stringent factor to the ribosome.

2. Formation of the unusual nucleotide ppGpp.

3. Formation of the unusual nucleotide pppGpp.

4. Uncharged tRNA binds in the ribosomal A-site.

#Question id: 1500

#Unit 4. Cell Communication and Cell Signaling

Which of the following is not a normal function of p53?

#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?