SOLVED

45. One third of all cancer deaths are due to mutations that arise from smoking tobacco. 46. Which of the following situations would be considered an example of positive regulation of gene expression in a prokaryote? A. The CAP protein regulating the lac operon to be active when glucose is absent and lactose is present. B. The CAP protein regulating the lac operon to be active when lactose is absent and glucose is present. C. The repressor protein regulating the lac operon to be active when glucose is absent and lactose is present. D. The repressor protein regulating the lac operon to be active when lactose is absent and glucose is present. 47. If CAP is absent from a cell what are the potential consequences? A. The individual cannot activate the catabolism of various other metabolites in the absence of glucose. B. The individual does not have a backup system for survival when glucose is absent. C. The individual will most likely die because they cannot metabolize enough energy if glucose is absent. D. All of these are consequences of the absence of CAP. 48. Which of the following problems can arise during posttransriptional control? A. Differential splicing of exons that can lead to an altered gene expression. B. Not excising all of introns from the pre-mRNA strand, leaving fragments to be joined with the exons. C. Excising an exon from the pre-mRNA strand. D. All of these are errors that can occur during posttranscriptional control of gene expression. 49. Which of the following series of events is associated with the formation of cancer? A. The proto-oncogenes mutate and become oncogenes which are continuously active. There is also an associated loss of tumor suppressor gene activity allowing uncontrolled growth of cells. B. The oncogenes mutate and become proto-oncogenes which are continuously active. There is also an associated loss of tumor suppressor gene activity allowing uncontrolled growth of cells. C. The proto-oncogenes mutate and become oncogenes which stop functioning altogether. There is also an associated increase in the tumor suppressor gene activity allowing uncontrolled growth of cells. D. The oncogenes mutate and become proto-oncogenes which stop functioning altogether. There is also an associated increase in the tumor suppressor gene activity allowing uncontrolled growth of cells. 50. What complications could arise if an individual had a genetic disorder that prevented them from forming 25% of their histones? A. The chromatin would not condense properly and some of it would not be available for transcriptional machinery resulting in the expression of additional genes. B. The chromatin would not condense properly and some of it would not be available for transcriptional machinery resulting in the decreased expression of their genes. C. The chromatin would condense more than normal and result in the expression of additional genes. D. The chromatin would condense more than normal and result in the expression of fewer than normal genes. Â Â