Question 1

Gene expression might be altered at the level of post-transcriptional processing in eukaryotes rather than prokaryotes because of which of the following?

Accepted Answer

A) Eukaryotic mRNAs get 5' caps and 3' tails. 
B) Prokaryotic genes are expressed as mRNA, which is more stable in the cell. 
C) Eukaryotic exons may be spliced in alternative patterns. 
D) Prokaryotes use ribosomes of different structure and size. 
E) Eukaryotic coded polypeptides often require cleaving of signal sequences before localization. 
A) Eukaryotic mRNAs get 5' caps and 3' tails. 
B) Prokaryotic genes are expressed as mRNA, which is more stable in the cell. 
C) Eukaryotic exons may be spliced in alternative patterns. 
D) Prokaryotes use ribosomes of different structure and size. 
E) Eukaryotic coded polypeptides often require cleaving of signal sequences before localization.

Question 2

Which of the following genes map out the basic subdivisions along the anterior-posterior axis of the Drosophila embryo?

Accepted Answer

A) homeotic genes 
B) segmentation genes 
C) egg-polarity genes 
D) morphogens 
E) inducers 
A) homeotic genes 
B) segmentation genes 
C) egg-polarity genes 
D) morphogens 
E) inducers

Question 3

Use the following information to answer the questions below.
Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome.
-If she moves the promoter for the lac operon to the region between the beta galactosidase gene and the permease gene, which of the following would be likely?

Accepted Answer

A) Three structural genes will no longer be expressed. 
B) RNA polymerase will no longer transcribe permease. 
C) The operon will no longer be inducible. 
D) Beta galactosidase will be produced. 
E) The cell will continue to metabolize but more slowly. 
A) Three structural genes will no longer be expressed. 
B) RNA polymerase will no longer transcribe permease. 
C) The operon will no longer be inducible. 
D) Beta galactosidase will be produced. 
E) The cell will continue to metabolize but more slowly.

Question 4

Which of the following describes the function of an enzyme known as Dicer?

Accepted Answer

A) It degrades single-stranded DNA. 
B) It degrades single-stranded mRNA. 
C) It degrades mRNA with no poly-A tail. 
D) It trims small double-stranded RNAs into molecules that can block translation. 
E) It chops up single-stranded DNAs from infecting viruses. 
A) It degrades single-stranded DNA. 
B) It degrades single-stranded mRNA. 
C) It degrades mRNA with no poly-A tail. 
D) It trims small double-stranded RNAs into molecules that can block translation. 
E) It chops up single-stranded DNAs from infecting viruses.

Question 5

One way scientists hope to use the recent knowledge gained about noncoding RNAs lies with the possibilities for their use in medicine. Of the following scenarios for future research, which would you expect to gain most from RNAs?

Accepted Answer

A) exploring a way to turn on the expression of pseudogenes 
B) targeting siRNAs to disable the expression of an allele associated with autosomal recessive disease 
C) targeting siRNAs to disable the expression of an allele associated with autosomal dominant disease 
D) creating knock-out organisms that can be useful for pharmaceutical drug design 
E) looking for a way to prevent viral DNA from causing infection in humans 
A) exploring a way to turn on the expression of pseudogenes 
B) targeting siRNAs to disable the expression of an allele associated with autosomal recessive disease 
C) targeting siRNAs to disable the expression of an allele associated with autosomal dominant disease 
D) creating knock-out organisms that can be useful for pharmaceutical drug design 
E) looking for a way to prevent viral DNA from causing infection in humans

Question 6

If glucose is available in the environment of E. coli, the cell responds with a very low concentration of cAMP. When the cAMP increases in concentration, it binds to CAP. Which of the following would you expect to be a measurable effect?

Accepted Answer

A) decreased concentration of the lac enzymes 
B) increased concentration of the trp enzymes 
C) decreased binding of the RNA polymerase to sugar metabolism-related promoters 
D) decreased concentration of alternative sugars in the cell 
E) increased concentrations of sugars in the cell 
A) decreased concentration of the lac enzymes 
B) increased concentration of the trp enzymes 
C) decreased binding of the RNA polymerase to sugar metabolism-related promoters 
D) decreased concentration of alternative sugars in the cell 
E) increased concentrations of sugars in the cell

Question 7

There is a mutation in the repressor that results in a molecule known as a super-repressor because it represses the lac operon permanently. Which of these would characterize such a mutant?

Accepted Answer

A) It cannot bind to the operator. 
B) It cannot make a functional repressor. 
C) It cannot bind to the inducer. 
D) It makes molecules that bind to one another. 
E) It makes a repressor that binds CAP. 
A) It cannot bind to the operator. 
B) It cannot make a functional repressor. 
C) It cannot bind to the inducer. 
D) It makes molecules that bind to one another. 
E) It makes a repressor that binds CAP.

Exam 18: Regulation of Gene Expression

Gene expression might be altered at the level of post-transcriptional processing in eukaryotes rather than prokaryotes because of which of the following?

Which of the following genes map out the basic subdivisions along the anterior-posterior axis of the Drosophila embryo?

Which of the following describes the function of an enzyme known as Dicer?

One way scientists hope to use the recent knowledge gained about noncoding RNAs lies with the possibilities for their use in medicine. Of the following scenarios for future research, which would you expect to gain most from RNAs?

If glucose is available in the environment of E. coli, the cell responds with a very low concentration of cAMP. When the cAMP increases in concentration, it binds to CAP. Which of the following would you expect to be a measurable effect?

There is a mutation in the repressor that results in a molecule known as a super-repressor because it represses the lac operon permanently. Which of these would characterize such a mutant?

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Viruses

Dna Tools and Biotechnology

Genomes and Their Evolution

Descent With Modification: a Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity Ii: the Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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