Question

3. Which of the following are true of chemotherapeutic agents? Select all that apply.

The adverse side-effects of chemotherapeutics are strongest in cell types that dividing rapidly (hair, blood and GI tract).

  

They create broken chromosomes or stalled replication forks.

These agents are toxic to cancer cells because they are part of a tumor.

The cytotoxic effect of these DNA damaging agents requires the cell to be actively dividing.

4.  

Which statement below best describes an oncogene?

Gene that encodes for a protein that drives cell division forward.

Gene that encodes for a protein that blocks the cell cycle

5.  

Which of the following is a correct pairing of a base to the product of its deamination?

  

Thymidine to uracil

   

Adenine to xanthine

   

5-methylcytosine to thymine

   

Cytosine to thymine

6.

Which of the following correctly describes the mechanism of a deamination reaction?

  

The 3' OH group attacks the nitrogen of a base.

An OH group from water attacks the base removing the amine group.

7.

The Ames test requires a specific strain of Salmonella that (select all that apply):

  

requires a lack of histidine in the media to survive.

may be able to survive without histidine if they get the proper reversion mutation.

  

is resistant to mutations.

   

is a histidine auxotroph.

Answer 1

3. Chemotherapeitic agents work well on the cell that are actively dividing. Therefore, option a and option d are correct.

4. Oncogene is a gene that have the potential to cause cancer. It encode a protein that move cell cycle forward. Hence, option a is correct.

5. Correct example of deamination where 5- methylcytosine to thymine. Hence, option c is correct.

6. Deamination is the process of removing amine group using OH y. Hence, option b is correct.

7. Ames test is used to test mutagens and done by salmonella bacteria who is histidine auxotroph and able to survive without histidine if they get proper reversion mutation. Hence, option b and d are correct.