INTERPRETING THE GRAPH The 31 different cancers represented in the figure above were chosen because reliable data existed in the literature on two variables: lifetime (80 years) risk of cancer and the total number of stem cell divisions that occur in that tissue during a lifetime. Lifetime risk is shown on the y-axis and is expressed as the base 10 logarithm of the probability of a person developing the cancer. For example, a lifetime risk of 10^-2-3 is a 1% lifetime risk. Therefore, the risk of a person developing thyroid cancer over the course of an 80-year lifespan is about 1 in 100. The x-axis shows the estimated total number of stem cell divisions within a particular tissue type beginning with the first precursor cells. This number was calculated based on the total number of stem cells in the developed tissue and the rate of normal cell turnover within that tissue. The researchers focused on stem cells because most fully differentiated cells are short-lived and are therefore unlikely to produce cancerous cells. QUESTIONS - Answer in 1-2 pages. What is a stem cell? Find the answer in your textbook. What trends do you notice in the figure above? What do the trends in this figure tell you about the relationship between stem cell divisions and cancer? Why do you think researchers focused on stem cells rather than fully differentiated cells? How much higher is the risk of lung cancer in smokers than in nonsmokers? Based on the information above, would you expect the risk of cancer to increase or decrease as a person gets older? Why?
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What is a stem cell? A stem cell is an undifferentiated cell that has the potential to develop into many different cell types in the body during early life and growth. They can also serve as a sort of internal repair system, dividing without limit to replenish Show more…
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Question 12 Cigar smoking and cancer: The Journal of the National Cancer Institute (Feb 16, 2000) published the results of a study that investigated the association between cigar smoking and death from tobacco-related cancers. Data were obtained for a national sample of 137,243 American men. The results are summarized in the table below. Each male in the study was classified according to his cigar-smoking status and whether or not he died from tobacco-related cancer: Died from Cancer Cigars Never Smoked Former Smoker Current Smoker Totals Yes 782 91 141 1,014 No 120,747 7,757 7,725 136,229 Totals 121,529 7,848 7,866 137,243 Find the probability that a randomly selected man never smoked cigars and died from cancer: Use significant decimal places for your answer; and use the proper rules of rounding. I am looking for just the answer; not the equation. Question 13 Cigar smoking and cancer: The Journal of the National Cancer Institute (Feb 16, 2000) published the results of a study that investigated the association between cigar smoking and death from tobacco-related cancers. Data were obtained for a national sample of 137,243 American men. The results are summarized in the table below. Each male in the study was classified according to his cigar-smoking status and whether or not he died from tobacco-related cancer: Died from Cancer Cigars Never Smoked Former Smoker Current Smoker Totals Yes 782 91 141 1,014 No 120,747 7,757 7,725 136,229 Totals 121,529 7,848 7,866 137,243 Find the probability that a randomly selected man was a former cigar smoker and did not die from cancer; Use significant decimal places for your answer; and use the proper rules of rounding. I am looking for just the answer, not the equation.
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