Question 1

In the lac operon of E. coli, if the lacI region was moved to a different section of the chromosome, but was otherwise unchanged, the most likely result would be that

Accepted Answer

A)  the repressor protein would not be synthesised, so expression of the lac operon would become constitutive. 
B)  the repressor protein would always be synthesised, so expression of the lac operon would always be repressed. 
C)  the repressor protein would exert its normal effect on the expression of the lac operon because the lacI gene can act in trans. 
D)  expression of the lac operon would depend on different repressors, depending on where the lacI was integrated into the chromosome. 
E)  expression of the lac operon would remain normal because the lacI gene is not involved in the regulation of the lac operon. 
A)  the repressor protein would not be synthesised, so expression of the lac operon would become constitutive. 
B)  the repressor protein would always be synthesised, so expression of the lac operon would always be repressed. 
C)  the repressor protein would exert its normal effect on the expression of the lac operon because the lacI gene can act in trans. 
D)  expression of the lac operon would depend on different repressors, depending on where the lacI was integrated into the chromosome. 
E)  expression of the lac operon would remain normal because the lacI gene is not involved in the regulation of the lac operon.

Question 2

In the regulation of gene expression, negative regulation

Accepted Answer

A)  induces transcription of a gene in response to environmental conditions. 
B)  alters the DNA sequence to contain a nonsense mutation. 
C)  represses transcription of a gene in response to environmental conditions. 
D)  increases the production of regulatory proteins. 
E)  causes a gene to be expressed constitutively. 
A)  induces transcription of a gene in response to environmental conditions. 
B)  alters the DNA sequence to contain a nonsense mutation. 
C)  represses transcription of a gene in response to environmental conditions. 
D)  increases the production of regulatory proteins. 
E)  causes a gene to be expressed constitutively.

Question 3

A unicellular protist lives in the gut of an insect that eats wood. The protist gains its energy by first breaking the cellulose into sucrose, which it can use. The insect is brought into a lab and fed on a starch solution, which induces a different set of metabolic genes. You would expect the protist to

Accepted Answer

A)  starve. 
B)  switch off genes for manufacturing cellulases. 
C)  switch off genes for the degradation of sucrose. 
D)  manufacture cellulose. 
E)  induce genes to manufacture cellulase. 
A)  starve. 
B)  switch off genes for manufacturing cellulases. 
C)  switch off genes for the degradation of sucrose. 
D)  manufacture cellulose. 
E)  induce genes to manufacture cellulase.

Question 4

If a protein repression complex contained a faulty enzyme that could no longer remove acetyl groups from histones, the most likely outcome would be that

Accepted Answer

A)  gene expression would decrease because RNA polymerase would be unable to bind to the promoter region. 
B)  gene expression would neither increase nor decrease because the acetylation of histones is not involved in the regulation of gene expression. 
C)  DNA would not be able to be expressed because of the formation of tightly bound nucleosomes. 
D)  the protein repressor complex would be degraded by endonucleases. 
E)  gene expression would become constitutive. 
A)  gene expression would decrease because RNA polymerase would be unable to bind to the promoter region. 
B)  gene expression would neither increase nor decrease because the acetylation of histones is not involved in the regulation of gene expression. 
C)  DNA would not be able to be expressed because of the formation of tightly bound nucleosomes. 
D)  the protein repressor complex would be degraded by endonucleases. 
E)  gene expression would become constitutive.

Question 5

Which of the following is NOT a control mechanism utilised by eukaryote cells?

Accepted Answer

A)  Stability of mRNA. 
B)  Blockage of transcription. 
C)  The lac operon. 
D)  Rate of enzyme destruction. 
E)  Production of microRNA. 
A)  Stability of mRNA. 
B)  Blockage of transcription. 
C)  The lac operon. 
D)  Rate of enzyme destruction. 
E)  Production of microRNA.

Exam 12: Gene Expression

In the lac operon of E. coli, if the lacI region was moved to a different section of the chromosome, but was otherwise unchanged, the most likely result would be that

In the regulation of gene expression, negative regulation

If a protein repression complex contained a faulty enzyme that could no longer remove acetyl groups from histones, the most likely outcome would be that

Which of the following is NOT a control mechanism utilised by eukaryote cells?

Nature of Molecules

Biomolecules

The Chemistry of Life

Functioning Cells

Movement Across Membranes

Harvesting Energy

Cells, Tissues and Signals

Cell Division

Inheritance

Genes, Chromosomes and Dna

The Genetic Code

Genomes, Mutation and Cancer

Viruses

Genetic Engineering and Biotechnology

Reproduction, Growth and Development of Flowering Plants

Structure of Plants

Plant Nutrition, Transport and Adaptation to Stress

Plant Hormones and Growth Responses

Animal Reproduction

Animal Development

Homeostasis: Water, Solutes and Excretion

Gas Exchange in Animals

Circulation

Metabolism, Temperature Regulation and Environmental Stress

Animal and Human Nutrition

Innate Defences and the Immune System

Hormonal Control in Animals

Nervous Systems

Animal Movement

Animal Behaviour

Evolving Life

Evolving Earth

Mechanisms of Evolution

Bacteria

The Protists

Plants

Fungi

Simple Animals: Sponges to Flatworms

Annelids, Molluscs, Nematodes and Arthropods

Echinoderms and Chordates

Australian Biota

Population Ecology

Living in Communities

Ecosystems

Human Impacts

Filters