The thermoacidophile, Sulfolobus acidocaldarius lacks peptidoglycan. What is likely to be true of this species?

1. It is a bacterium.

2. It is an archaean.

3. The optimal pH of its enzymes will lie above pH 7.

4. The optimal pH of its enzymes will lie below pH 7.

5. It could inhabit certain hydrothermal springs.

6. It could inhabit alkaline hot springs.

#Question id: 1399

#Unit 4. Cell Communication and Cell Signaling

Loss-of-function mutations in which of the following genes typifies colorectal carcinomas?

a. myc              b. K-ras                       c. p53              d. APC

#Question id: 1400

#Unit 4. Cell Communication and Cell Signaling

Which property is shared by malignant tumor cells and transformed cells in culture?

a. reduced growth factor requirement                        b. attachment-dependent growth

c. loss of actin microfilaments                                    d. altered morphology

#Question id: 1401

#Unit 4. Cell Communication and Cell Signaling

Which of the following are proto-oncogenes?

a. fos               b. myc             c. p53              d. ras               e. Rb

#Question id: 1402

#Unit 4. Cell Communication and Cell Signaling

Which of the following oncoproteins possess(es) protein kinase activity?

#Question id: 1403

#Unit 4. Cell Communication and Cell Signaling

Tumor-suppressor genes encode proteins with which of the following functions?

a. growth-promoting               b. growth-arresting                  c. pro-apoptotic

d. anti-apoptotic                      e. DNA repair

#Question id: 1404

#Unit 4. Cell Communication and Cell Signaling

Which of the following are transcription factors?