Genetics: From Genes to Genomes
6th Edition
ISBN: 9781259700903
Author: Leland Hartwell Dr., Michael L. Goldberg Professor Dr., Janice Fischer, Leroy Hood Dr.
Publisher: McGraw-Hill Education
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Textbook Question
Chapter 16, Problem 33P
Many genes whose expression is turned on by DNA damage have been isolated. Loss-of-function mutations in the lexA gene lead to the expression of many of these genes, even when there has been no DNA damage. Would you hypothesize that LexA protein is a positive or a negative regulator? Why?
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Chapter 16 Solutions
Genetics: From Genes to Genomes
Ch. 16 - For each of the terms in the left column, choose...Ch. 16 - The following statement occurs early in this...Ch. 16 - One of the main lessons of this chapter is that...Ch. 16 - All mutations that abolish function of the Rho...Ch. 16 - The figure at the beginning of this chapter shows...Ch. 16 - The promoter of an operon is the site to which RNA...Ch. 16 - You are studying an operon containing three genes...Ch. 16 - You have isolated a protein that binds to DNA in...Ch. 16 - You have isolated two different mutants reg1 and...Ch. 16 - Bacteriophage , after infecting a cell, can...
Ch. 16 - Mutants were isolated in which the constitutive...Ch. 16 - Suppose you have six strains of E. coli. One is...Ch. 16 - The previous problem raises some interesting...Ch. 16 - For each of the E. coli strains containing the lac...Ch. 16 - For each of the following growth conditions, what...Ch. 16 - For each of the following mutant E. coli strains,...Ch. 16 - Maltose utilization in E. coli requires the...Ch. 16 - Seven E. coli mutants were isolated. The activity...Ch. 16 - Cells containing missense mutations in the crp...Ch. 16 - Six strains of E.coli mutants 16 that had one of...Ch. 16 - a. The original constitutive operator mutations in...Ch. 16 - In an effort to determine the location of an...Ch. 16 - Prob. 23PCh. 16 - The footprinting experiment described in Fig....Ch. 16 - Why is the trp attenuation mechanism unique to...Ch. 16 - a. How many ribosomes are required at a minimum...Ch. 16 - The following is a sequence of the leader region...Ch. 16 - For each of the E. coli strains that follow,...Ch. 16 - Prob. 29PCh. 16 - For each element in the list that follows,...Ch. 16 - Among the structurally simplest riboswitches are...Ch. 16 - Great variation exists in the mechanisms by which...Ch. 16 - Many genes whose expression is turned on by DNA...Ch. 16 - In 2005, Frederick Blattner and his colleagues...Ch. 16 - The E.coli MalT protein is a positive regulator of...Ch. 16 - Prob. 36PCh. 16 - Prob. 37PCh. 16 - Prob. 38PCh. 16 - Prob. 39PCh. 16 - Prob. 40PCh. 16 - Prob. 41PCh. 16 - The researchers who investigated bioluminescence...Ch. 16 - Prob. 43PCh. 16 - Quorum sensing controls the expression of...Ch. 16 - Scientists are currently screening a chemical...
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- Given the following schematic for a gene and its associated regulatory regions, answer the following questions by placing the correct letter in the provided blanks please put in the correct letter for the questions What region would provide cell type-specific expression of genes? region What site would significantly increase gene expression rates? = region What region or regions of this gene’s coding sequence are expressed as amino acids = regionarrow_forwardYou have isolated different mutants (reg1 and reg2) causing constitutive expression of the emu operon (which has genes emu1 and emu2). One mutant contains a defect in a DNA-binding site, and the other has a loss-of-function defect in the gene encoding a protein that binds to the site. Is the DNA-binding protein a positive or negative regulator of gene expression?arrow_forwardLysR regulators like llvY repress transcription from their own promoters. This is called a negative feedback loop. Why might negative feedback be a good way to control expression of a transcriptional repressor? This type of negative feedback loop ensures that ilvC transcription will always be repressed when llvY levels are low, and ilvC will be transcribed highly when llvY levels are high. This type of negative feedback regulation ensures that ilvY is never transcribed. Since llvY is a transcriptional repressor, it will slow down cell growth by blocking transcription. So, llvY represses it's own transcription so that no llvY can ever be made, and the cell can grow. This type of negative feedback loop ensures that there is always a moderate amount of llvY. When IlvY levels fall too low, transcription from the promoter will increase since IlvY won't be able to repress it's own promoter. This negative feedback also ensures that IlVY levels don't rise too high - when llvY levels are high,…arrow_forward
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