1. Tobacco contains many carcinogens (chemicals that cause cancer). Two of the major carcinogens in tobacco that cause cancer in humans are BaP and NNK. Match the 2 carcinogens with the way in which they are formed in the tobacco.

When tobacco is “cured” or prepared for either smokeless or smoked forms, this chemical is produced from nicotine in the tobacco: NNK.

As tobacco is burned, this chemical is produced as part of the combustion process: BAP (benzo[a]pyrene).

2. It only takes one carcinogen to produce one mutation that can cause cancer. Name one gene that is mutated by carcinogens such as BaP leading to the development of cancer. p53

What is the function of the protein that is synthesized under instructions of this gene? The p53 protein directs cells with damaged or mutated DNA to commit “suicide” or apoptosis.

3. Nicotine, in the absence of any tobacco, can also help tumors form. How can this happen? Circle your answer(s).

1. Nicotine causes DNA damage
2. Nicotine prevents chemotherapy drugs from killing cancer cells
3. Nicotine causes tumor growth
4. All of the above

4. Suppose people could get “telomere tested” when they go for their annual health checkup. They would give a cheek swab sample, and the lab would check the telomere length of their chromosomes. Can you match which chromosome is most likely found for each of the people below? (draw an arrow to connect the telomere with the people)

5. It usually takes years to develop cancer after smoking or using smokeless tobacco. But how long does it take to form a mutation in DNA, which is one of the first steps in developing cancer? One way to find out is to participate in a real experiment. You can do this experiment in a laboratory or follow along with a video of other students performing the experiment in a lab.

Before you start, indicate what you think the answers are to the following questions by checking the item:

1. Can exposure to tobacco cause a mutation in DNA without smoking it?  Yes____  No____
2. How long would it take for tobacco to cause a mutation?  Hours____ Days____ Months____ Years____

Now, consult your lab packet to do the experiment—you can watch the video and then collect your own data. When you have finished, answer the following questions:

1. Could the tobacco cause a mutation in DNA without smoking it?  Yes____  No___
2. How long did it take for tobacco to cause a mutation?  Hours____ Days____ Months____ Years____
3. Do your answers agree or disagree with your prediction above?  Agree____  Disagree____
4. Now that you have determined how tobacco from one cigarette can cause a change in bacterial DNA, how could you test whether nicotine alone could cause a mutation in DNA? Use the lab activity you just saw in the video or in your Lab Activity packet to help guide your answer.

Get some pure nicotine and apply it to the Petri dish. Add the bacteria and let them grow for a few days. Look at the bacteria to see if any colonies turn white. This indicates that the nicotine produces DNA mutations in the bacteria.