BIO 1A03 TEST 2 QUESTIONS AND ANSWERS ALREADY PASSED

BIO 1A03 TEST 2 QUESTIONS AND ANSWERS ALREADY PASSED The lacZand lacY genes are transcribed when a) lactose is absent and glucose levels are high. b)lactose is present and glucose levels are low. c)lactose is present, regardless of the level of glucose in the cell. d) glucose levels are low, regardless of the level of lactose in the cell. b) The CRP-cAMP complex binds the lactose operon when a) glucose levels and cAMP levels are low. b) glucose levels are high and cAMP levels are low. c) glucose levels and cAMP levels are high. d) glucose levels are low and cAMP levels are high d) As E.coli cells transition from glucose to lactose metabolism when a) there is an increase in the amount of detectable lactose permease. b) there is a decrease in the amount of detectable beta-galactosidase. c) there is an increase in the amount of glucose that is consumed. d) lactose permease is secreted by the bacterial cell into the environment. a) When glucose is no longer available as a nutrient source for bacteria, and lactose becomes the predominant nutrient source, beta-galactosidase production a) is regulated at the translational level. b) is not regulated in any manner. c) is regulated at the transcriptional level. d) is regulated at the post-translational level. c) When considering the regulation of gene expression a)translational regulation would be the slowest. b) post-translational regulation would be the fastest. c) transcriptional regulation would be the fastest. d) translational regulation would be the most efficient. b) The term gene expression refers to a) transcription, translation and post-translational modifications of the functional gene product. b) the process of transcribing DNA into mRNA. c) the post-translational modifications of a protein. d) the transcription and subsequent translation of a protein coding gene. a) When growing bacterial cells in an environment containing only a limited amount of glucose as a nutrient source a) bacterial growth is arrested once all the glucose is depleted. b) bacterial switch to utilizing lactose as a source of energy. c) there is no change in bacterial growth once glucose is depleted. d) bacterial growth is accelerated once all the glucose is depleted. a) Housekeeping genes a) allow for the production of enzymes during changes in cell division. b) include genes that are important for structural proteins of the cell. c) are transcribed and translated to bring about changes in cell growth. d) are expressed on an as-needed basis. b) Genes that are turned on and off on an as-needed basis are often referred to as a) housekeeping genes. b) constitutively expressed. c) genes that are required all of the time for normal cellular function. d) regulated genes. d) A group of related genes with similar functions that are found clustered together along the bacterial chromosome, is often referred to as a) an operon. b) a promoter. c) a regulator. d) an operator. a) The beta-galactosidase gene a) is always turned on. b) is transcribed in the presence of glucose. c) is constitutively expressed. d) is expressed in the presence of lactose and when no glucose is available. d) _______________________ is the enzyme that can metabolize lactose in bacteria. a) Lactose permease b) Amylase c) Galactose d) Beta-galactosidase d) Protein degradation of misfolded proteins is accomplished a) by tagging these proteins with miRNA followed by degradation inside the proteasome. b) by specific targeted destruction that is carried out by siRNA. c) by tagging these proteins with components of the proteasome complex. d) by tagging these proteins with small ubiquitin proteins that form a polyubiquitin chain. Score: 0 of 1 d) Both miRNA and siRNA work in conjunction with a) RNA polymerase to bind RNA transcripts in the nucleus. b) a protein complex called RISC to bind RNA transcripts in the cytoplasm. c) hairpin structures to bind RNA transcripts in the cytoplasm. d) a protein complex called RISC to bind RNA transcripts in the nucleus. b) When interpreting DNA microarray analysis and comparing two genes, an active gene will be detected a) as having a brighter signal due to the presence of a many more molecules of mRNA. b) as having a brighter signal due to the presence of lower amounts cDNA after reverse transcription. c) as having a dimmer signal due to the presence