front 1 Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If she moves the promoter for the lac operon to the region between the beta galactosidase (lacZ) gene and the permease (lacY) gene, which of the following would be likely?
| back 1 Beta galactosidase will not be produced |
front 2 If she moves the operator to the far end of the operon, past the transacetylase (lacA) gene, which of the following would likely occur when the cell is exposed to lactose?
| back 2 The structural genes will be transcribed continuously |
front 3 If she moves the repressor gene (lac I), along with its promoter, to a position some several thousand base pairs away from its normal position, which will you expect to occur?
| back 3 The lac operon will function normally |
front 4 A geneticist introduces a transgene into yeast cells and isolates five independent cell lines in which the transgene has integrated into the yeast genome. In four of the lines, the transgene is expressed strongly, but in the fifth there is no expression at all. Which of the following is a likely explanation for the lack of transgene expression in the fifth cell line?
Acetylation. | back 4 The transgene integrated into a heterochromatic region of the genome |
front 5 Of the lines that express the transgene, one is transcribed but not translated. Which of the following is a likely explanation?
| back 5 no AUG in any frame |
front 6 A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. In one set of experiments she succeeded in decreasing methylation of histone tails. Which of the following results would she most likely see?
| back 6 decreased chromatin condensation |
front 7 One of her colleagues suggested she try increased methylation of C nucleotides in a mammalian system. Which of the following results would she most likely see?
| back 7 inactivation of the selected genes |
front 8 A researcher introduces double-stranded RNA into a culture of mammalian cells, and can identify its location or that of its smaller subsections experimentally, using a fluorescent probe. In addition, she finds other evidence of this single-stranded RNA piece’s activity?
| back 8 The rate of accumulation of the polypeptide encoded by the target mRNA is reduced. |
front 9 If a particular operon encodes enzymes for making an essential amino
acid and is regulated | back 9 the amino acid acts as a corepressor. |
front 10 The functioning of enhancers is an example of | back 10 transcriptional control of gene expression. |
front 11 Which of the following is an example of post-transcriptional control
of gene expression? | back 11 the removal of introns and alternative splicing of exons |
front 12 What would occur if the repressor of an inducible operon were mutated
so it could not bind | back 12 continuous transcription of the operon's genes |
front 13 Which of the following statements about the DNA in one of your brain
cells is true? | back 13 It is the same as the DNA in one of your kidney cells. |
front 14 Which of the following would not be true of cDNA produced using human
brain tissue as the | back 14 It would contain sequences representing all the genes in the genome. |