Question 1

A mutation in the lacI gene prevents the gene product from binding allolactose. What will the expression level of the operon be in the absence of lactose?

Accepted Answer

A) no transcription 
B) postive regulation 
C) constitutively active 
D) low level of expression 
A) no transcription 
B) postive regulation 
C) constitutively active 
D) low level of expression A

Question 2

A deletion in an operon removes the terminator. How will that affect the transcript that is produced from the operon?

Accepted Answer

A) The transcript will be produced and normal in length 
B) The transcript will be produced, but shorter than normal 
C) The transcript will be produced, but longer than normal 
D) The transcript will produced, but will contain a deletion 
E)  The transcript will not be produced 
A) The transcript will be produced and normal in length 
B) The transcript will be produced, but shorter than normal 
C) The transcript will be produced, but longer than normal 
D) The transcript will produced, but will contain a deletion 
E)  The transcript will not be produced C

Question 3

A riboswitch only affects translation of an operon.

Accepted Answer

A) True 
 B)False  False

Question 4

In the lac operon, the operator site is recognized by an activator protein.

Accepted Answer

A) True 
 B)False

Question 5

In the lac operon, the CAP site is located next to the ____________. When both lactose and glucose are present, this leads to a rate of transcription that is ___________.

Accepted Answer

A) terminator, low 
B) promoter, high 
C) terminator, high 
D) promoter, low 
A) terminator, low 
B) promoter, high 
C) terminator, high 
D) promoter, low

Question 6

What stem-loop conformations favor attenuation?

Accepted Answer

A) 1-2 
B) 1-2 and 2-3 
C) 2-3 
D) 1-2 and 3-4 
A) 1-2 
B) 1-2 and 2-3 
C) 2-3 
D) 1-2 and 3-4

Question 7

In Jacob, Monod, and Pardee's experiment, what would have been the conclusion if all four tubes produced a yellow color when b-ONPG was added?

Accepted Answer

A) Expression of the lac operon is constitutive whether lacI is functional or not 
B) LacI provides the binding site for the repressor 
C) LacI encodes a diffusible repressor 
D) The researcher added too much b-ONPG 
A) Expression of the lac operon is constitutive whether lacI is functional or not 
B) LacI provides the binding site for the repressor 
C) LacI encodes a diffusible repressor 
D) The researcher added too much b-ONPG

Question 8

Repressor proteins are responsible for negative transcriptional regulation.

Accepted Answer

A) True 
 B)False

Question 9

Enzymes involved in metabolism are most likely regulated via _____.

Accepted Answer

A)  feedback inhibition 
B)  acetylation 
C)  methylation 
D)  none of the answers are correct 
A)  feedback inhibition 
B)  acetylation 
C)  methylation 
D)  none of the answers are correct

Question 10

In Jacob, Monod, and Pardee's experiment, how many functional copies of lacI were there in the merozygote?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
A)  0 
B)  1 
C)  2 
D)  3

Question 11

What is the gene responsible for attenuation in the trp operon?

Accepted Answer

A) trpL 
B) trpR 
C) trpD 
D) trpC 
A) trpL 
B) trpR 
C) trpD 
D) trpC

Question 12

The regulation of protein function is called ______.

Accepted Answer

A) posttranslational regulation 
B) transcriptional regulation 
C) translational regulation 
D) posttranscriptional regulation 
A) posttranslational regulation 
B) transcriptional regulation 
C) translational regulation 
D) posttranscriptional regulation

Question 13

In the lac operon, the operator is an example of a trans-effect genetic regulation.

Accepted Answer

A) True 
 B)False

Question 14

How many promoters are in an operon?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) It depends on how many genes are present in the operon 
A) 1 
B) 2 
C) 3 
D) It depends on how many genes are present in the operon

Question 15

DNA that contains instructions for two or more structural genes produces monocistronic mRNA.

Accepted Answer

A) True 
 B)False

Question 16

If CAP could not bind to its CAP site, then what would be the result? Assume lactose is present in each scenario.

Accepted Answer

A) Transcription would be difficult to repress in the presence of glucose 
B) Transcription would be difficult to activate in the presence of glucose 
C) Transcription would be difficult to activate in the absence of glucose 
A) Transcription would be difficult to repress in the presence of glucose 
B) Transcription would be difficult to activate in the presence of glucose 
C) Transcription would be difficult to activate in the absence of glucose

Question 17

Operons that code for catabolic enzyme systems are typically regulated by repressors.

Accepted Answer

A) True 
 B)False

Question 18

An enzyme catalyzes a substrate into a final product. When the concentration of the final product is high enough, it binds to a regulatory site on the enzyme. This binding at the regulatory site changes the shape of the enzyme, which prevents it from binding the substrate and prevents formation of more final product. This is an example of a(n) _______________.

Accepted Answer

A) posttranslational modification 
B) allosteric enzyme 
C) translational repressor 
D) methylation 
A) posttranslational modification 
B) allosteric enzyme 
C) translational repressor 
D) methylation

Question 19

A deletion in an operon removes the promoter. How will that affect the transcript that is produced from the operon?

Accepted Answer

A) The transcript will be produced and normal in length 
B) The transcript will be produced, but shorter than normal 
C) The transcript will be produced, but longer than normal 
D) The transcript will produced, but will contain a deletion 
E)  The transcript will not be produced 
A) The transcript will be produced and normal in length 
B) The transcript will be produced, but shorter than normal 
C) The transcript will be produced, but longer than normal 
D) The transcript will produced, but will contain a deletion 
E)  The transcript will not be produced

Question 20

For these questions, match the following to its appropriate letter. Use each letter only once.

Accepted Answer

The answer of For these questions, match the following to...

Exam 14: Gene Regulation in Bacteria

A mutation in the lacI gene prevents the gene product from binding allolactose. What will the expression level of the operon be in the absence of lactose?

A deletion in an operon removes the terminator. How will that affect the transcript that is produced from the operon?

A riboswitch only affects translation of an operon.

In the lac operon, the operator site is recognized by an activator protein.

In the lac operon, the CAP site is located next to the ____________. When both lactose and glucose are present, this leads to a rate of transcription that is ___________.

What stem-loop conformations favor attenuation?

In Jacob, Monod, and Pardee's experiment, what would have been the conclusion if all four tubes produced a yellow color when b-ONPG was added?

Repressor proteins are responsible for negative transcriptional regulation.

Enzymes involved in metabolism are most likely regulated via _____.

In Jacob, Monod, and Pardee's experiment, how many functional copies of lacI were there in the merozygote?

What is the gene responsible for attenuation in the trp operon?

The regulation of protein function is called ______.

In the lac operon, the operator is an example of a trans-effect genetic regulation.

How many promoters are in an operon?

DNA that contains instructions for two or more structural genes produces monocistronic mRNA.

If CAP could not bind to its CAP site, then what would be the result? Assume lactose is present in each scenario.

Operons that code for catabolic enzyme systems are typically regulated by repressors.

A deletion in an operon removes the promoter. How will that affect the transcript that is produced from the operon?

For these questions, match the following to its appropriate letter. Use each letter only once.

Overview of Genetics

Mendelian Inheritance

Chromosome Transmission During Cell Division and Sexual Reproduction

Extensions of Mendelian Inheritance

Non-Mendelian Inheritance

Genetic Linkage and Mapping in Eukaryotes

Genetic Transfer and Mapping in Bacteria and Bacteriophages

Variation in Chromosome Structure and Number

Molecular Structure of DNA and RNA

Chromosome Organization and Molecular Structure

DNA Replication

Gene Transcription and RNA Modification

Translation of MRNA

Gene Regulation in Eukaryotes I: Transcriptional Regulation

Gene Regulation in Eukaryotes II: Epigenetics and Regulation at the RNA Level

Genetics of Viruses

Gene Mutation and Dna Repair

Recombination and Transposition at the Molecular Level

DNA Technologies

Biotechnology

Genomics I: Analysis of DNA

Genomics II: Functional Genomics, Proteomics, and Bioinformatics

Medical Genetics and Cancer

Developmental Genetics

Population Genetics

Quantitative Genetics

Evolutionary Genetics

Filters

In the lac operon, the CAP site is located next to the __. When both lactose and glucose are present, this leads to a rate of transcription that is _.