Question 1

Alternative RNA processing generates different mRNAs that can direct the synthesis of different polypeptides.

Accepted Answer

A) True 
 B)False

Question 2

Compare and contrast positive and negative control of gene expression in bacteria.

Accepted Answer

Both forms of control result from an int

Question 3

Explain why lacOc mutations are cis -acting, whereas lacI mutations can be
trans -acting.

Accepted Answer

The operator region

Question 4

Alternative RNA processing can result in different mRNAs that start with different exons.

Accepted Answer

A) True 
 B)False

Question 5

(a) Describe by labeled diagram the structural components of the lac operon in E. coli.
a() State the function of the lac regulator gene.
b() State the function of fi -galactosidase in the lac system.
c() Show by diagram the manner in which lactose brings about transcription of the three structural genes of the lac operon.
d() Explain why certain mutations in the regulator gene (I -) of the lac system result in maximal synthesis of fi -galactosidase, permease, and transacetylase even in the
absence of the inducer (lactose).

Accepted Answer

(a) See appropriate diagrams in the text

Question 6

What type of genetic control, positive or negative, typically results when transcription factors interact with DNA?

Accepted Answer

The answer of What type of genetic control, positive or...

Question 7

Regarding eukaryotic and prokaryotic genetic regulation, what process seems to be the most similar between the two?

Accepted Answer

A)  intron/exon shuffling 
B)  transcriptional regulation 
C)  5' -capping regulation 
D)  RNA splicing regulation 
E)  poly -A tail addition 
A)  intron/exon shuffling 
B)  transcriptional regulation 
C)  5' -capping regulation 
D)  RNA splicing regulation 
E)  poly -A tail addition

Question 8

In the lac operon, the product of structural gene lacZ is capable of _.

Accepted Answer

A)  forming lactose from two glucose molecules 
B)  replacing hexokinase in the early steps of glycolysis 
C)  nonautonomous replication 
D)  splitting the fi -linkage of lactose 
E)  forming ATP from pyruvate 
A)  forming lactose from two glucose molecules 
B)  replacing hexokinase in the early steps of glycolysis 
C)  nonautonomous replication 
D)  splitting the fi -linkage of lactose 
E)  forming ATP from pyruvate

Question 9

The trp and lac operons are both subject to forms of control that are typically called negative.

Accepted Answer

A) True 
 B)False

Question 10

DNA methylation may be a significant mode of genetic regulation in eukaryotes. Methylation refers to _.

Accepted Answer

A)  changes in DNA -DNA hydrogen binding 
B)  alteration of DNA polymerase activity by addition of methyl groups to glycine residues 
C)  altering translational activity, especially of highly methylated tRNAs 
D)  addition of methyl groups to the cytosine of CG doublets 
E)  altering RNA polymerase activity by methylation 
A)  changes in DNA -DNA hydrogen binding 
B)  alteration of DNA polymerase activity by addition of methyl groups to glycine residues 
C)  altering translational activity, especially of highly methylated tRNAs 
D)  addition of methyl groups to the cytosine of CG doublets 
E)  altering RNA polymerase activity by methylation

Question 11

Under a system of positive control, transcription does not occur unless a regulator molecule directly stimulates RNA production.

Accepted Answer

A) True 
 B)False

Question 12

Mutations in the lacI and lacO genes of the lac regulatory system in E. coli often lead to full transcription of the three structural genes, even when no lactose is available to the organism. Such mutations would be called _.

Accepted Answer

The answer of Mutations in the lacI and lacO genes...

Question 13

Which of the following clusters of terms applies when addressing enhancers as elements associated with eukaryotic genetic regulation?

Accepted Answer

A)  cis -acting, variable orientation, variable position 
B)  cis -acting, fixed position, fixed orientation 
C)  cis -acting, variable position, fixed orientation 
D)  trans - and cis -acting, variable position 
E)  trans -acting, fixed position, fixed orientation 
A)  cis -acting, variable orientation, variable position 
B)  cis -acting, fixed position, fixed orientation 
C)  cis -acting, variable position, fixed orientation 
D)  trans - and cis -acting, variable position 
E)  trans -acting, fixed position, fixed orientation

Question 14

What symbols are used to describe constitutive mutations at specific regions of the lac
regulatory system?

Accepted Answer

The answer of What symbols are used to describe constitutive...

Question 15

The cAMP -CAP complex and RNA polymerase bind more efficiently to the lac operon together than either does alone. What term is applied to this increased efficiency of
binding?

Accepted Answer

The answer of The cAMP -CAP complex and RNA polymerase...

Question 16

In the diagram below, what type of control, positive or negative, is operating?

Accepted Answer

The answer of In the diagram below, what type of...

Question 17

Name at least three different levels of regulation in eukaryotes.

Accepted Answer

pretranscriptional,

Question 18

The catabolite repression system in E. coli essentially represses the lac operon when glucose is present. What evolutionary advantage would favor evolution of such a
system?

Accepted Answer

Glucose can enter glycolysis "as is," wh

Question 19

Transcription factors appear to be important molecules relating to the regulation of gene activity. In eukaryotes, two general classes or transcription factors exist. Briefly describe each.

Accepted Answer

One class assembles at promote

Question 20

The trp operon is typically characterized as being both under negative control and repressible.

Accepted Answer

A) True 
 B)False

Exam 15: Regulation of Gene Expression

Alternative RNA processing generates different mRNAs that can direct the synthesis of different polypeptides.

Compare and contrast positive and negative control of gene expression in bacteria.

Explain why lacOc mutations are cis -acting, whereas lacI mutations can be trans -acting.

Alternative RNA processing can result in different mRNAs that start with different exons.

What type of genetic control, positive or negative, typically results when transcription factors interact with DNA?

Regarding eukaryotic and prokaryotic genetic regulation, what process seems to be the most similar between the two?

In the lac operon, the product of structural gene lacZ is capable of _.

The trp and lac operons are both subject to forms of control that are typically called negative.

DNA methylation may be a significant mode of genetic regulation in eukaryotes. Methylation refers to _.

Under a system of positive control, transcription does not occur unless a regulator molecule directly stimulates RNA production.

Mutations in the lacI and lacO genes of the lac regulatory system in E. coli often lead to full transcription of the three structural genes, even when no lactose is available to the organism. Such mutations would be called _.

Which of the following clusters of terms applies when addressing enhancers as elements associated with eukaryotic genetic regulation?

What symbols are used to describe constitutive mutations at specific regions of the lac regulatory system?

The cAMP -CAP complex and RNA polymerase bind more efficiently to the lac operon together than either does alone. What term is applied to this increased efficiency of binding?

In the diagram below, what type of control, positive or negative, is operating?

Name at least three different levels of regulation in eukaryotes.

The catabolite repression system in E. coli essentially represses the lac operon when glucose is present. What evolutionary advantage would favor evolution of such a system?

Transcription factors appear to be important molecules relating to the regulation of gene activity. In eukaryotes, two general classes or transcription factors exist. Briefly describe each.

The trp operon is typically characterized as being both under negative control and repressible.

Introduction to Genetics

Mitosis and Meiosis

Mendelian Genetics

Modifications of Mendelian Ratios

Sex Determination and Sex Chromosomes

Chromosome Mutations: Variation in Number and Arrangement

Linkage and Chromosome Mapping in Eukaryotes

Genetic Analysis and Mapping in Bacteria and Bactierophages

DNA Structure and Analysis

DNA Replication and Recombination

Chromosome Structure and Dna Sequence Organization

The Genetic Code and Transcription

Translation and Proteins

Gene Mutation, Dna Repair, and Transposition

The Genetics of Cancer

Recombinant Dna Technology

Genomics and Proteomics

Applications and Ethics of Genetic Engineering and Biotechnology

Developmental Genetics

Quantitative Genetics and Multifactorial Traits

Population and Evolutionary Genetics

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