AP Bio Test Answers: Regulation of Gene Expression and Viruses.
AP Biology Regulation of Gene Expression and Viruses Exam Questions and Answers
1) What does the operon model attempt to explain? The coordinated control of gene expression in bacteria
2) The role of a metabolite that controls a repressible operon is to..? Bind to the repressor protein and activate it.
3) The tryptophan operon is a repressible operon that is…?Turned off whenever tryptophan is added to the growth medium.
4) This protein is produced by a regulatory gene.Repressor.
5) A lack of this nonprotein molecule would result in the inability of the cell to “turn off” genes:corepressor.
6) When this is taken up by the cell, it binds to the repressor so that the repressor no longer binds to the operator: inducer.
7) The lactose operon is likely to be transcribed when the cyclic AMP and lactose levels are both high within the cell.
8) Transcription of the structural genes in an inducible operon starts when the pathway’s substrate is present.
9) For a repressible operon to be transcribed, which of the following must occur? RNA polymerase must bind to the promoter, and the repressor must be inactive.
10) Which of the following mechanisms is (are) used to coordinately control the expression of multiple, related genes in eukaryotic cells? Organization of the genes into clusters, with local chromatin structures influencing the expression of all the genes at once.
11) If you were to observe the activity of methylated DNA, you would expect it to have turned off or slowed down the process of transcription.
12) Two potential devices that eukaryotic cells use to regulate transcription are DNA methylation and histone amplification.
13) In both eukaryotes and prokaryotes, gene expression is primarily regulated at the level of transcription.
14) During DNA replication, methylation of the DNA is maintained because methylation enzymes act at DNA sites where one strand is already methylated and thus correctly methylates daughter strands after replication.
15) In eukaryotes, general transcription factors bind to other proteins or to a sequence element within the promoter called the TATA box.