Question 1

RNA interference i s a process by which noncoding RNA molecules regulate gene expression.

Accepted Answer

A) True 
 B)False

Question 2

How does the first nucleotide at the 5 ′ end of a new mRNA chain differ from the other nucleotides in the chain?

Accepted Answer

A)  The first nucleotide is always a uracil. 
B)  The first nucleotide is always a cytosine. 
C)  The first nucleotide retains its triphosphate group, while the others do not. 
D)  The first nucleotide does not retain its triphosphate group, while the others in the chain do. 
E)  The first nucleotide is always a modified cytosine. 
A)  The first nucleotide is always a uracil. 
B)  The first nucleotide is always a cytosine. 
C)  The first nucleotide retains its triphosphate group, while the others do not. 
D)  The first nucleotide does not retain its triphosphate group, while the others in the chain do. 
E)  The first nucleotide is always a modified cytosine.

Question 3

Mobile genetic elements, such as transposons and retrotransposons, are significant because:

Accepted Answer

A)  the entire human genome is composed of transposons. 
B)  they are present in the human genome, but not in the genomes of other organisms. 
C)  mutations caused by retrotransposons contribute greatly to a species' evolution. 
D)  transposons are the only mechanisms of genetic diversity. 
E)  only corn contain transposons. 
A)  the entire human genome is composed of transposons. 
B)  they are present in the human genome, but not in the genomes of other organisms. 
C)  mutations caused by retrotransposons contribute greatly to a species' evolution. 
D)  transposons are the only mechanisms of genetic diversity. 
E)  only corn contain transposons.

Question 4

The total number of different three-base combinations of the four nucleic acid bases is:

Accepted Answer

A)  12. 
B)  16. 
C)  20. 
D)  64. 
E)  256. 
A)  12. 
B)  16. 
C)  20. 
D)  64. 
E)  256.

Question 5

tRNA molecules are able to act as adapters between amino acids and mRNA during translation because:

Accepted Answer

A)  tRNA binds to ribosomes. 
B)  tRNA can bind to both mRNA and an amino acid. 
C)  tRNA anticodons bind to amino acids. 
D)  tRNA is recognized by RNA polymerase. 
E)  tRNA molecules bind to promoter sequences to initiate transcription. 
A)  tRNA binds to ribosomes. 
B)  tRNA can bind to both mRNA and an amino acid. 
C)  tRNA anticodons bind to amino acids. 
D)  tRNA is recognized by RNA polymerase. 
E)  tRNA molecules bind to promoter sequences to initiate transcription.

Question 6

RNA synthesis is also known as:

Accepted Answer

A)  elongation. 
B)  reverse transcription. 
C)  termination. 
D)  translation. 
E)  transcription. 
A)  elongation. 
B)  reverse transcription. 
C)  termination. 
D)  translation. 
E)  transcription.

Question 7

Translation is initiated at the ____.

Accepted Answer

A)  AUG codon 
B)  UAG codon 
C)  anticodon 
D)  promoter 
E)  downstream sequence 
A)  AUG codon 
B)  UAG codon 
C)  anticodon 
D)  promoter 
E)  downstream sequence

Question 8

Transcription and translation occur simultaneously in prokaryotes. Why can't this process take place in eukaryotes? What disadvantage results from such linking in prokaryotes?

Accepted Answer

Concepts to Consider: The main barrier t

Question 9

Figure 13-3   Refer to the accompanying figure. The component labeled as B is:

Accepted Answer

A)  DNase. 
B)  DNA polymerase. 
C)  RNA primase. 
D)  RNA polymerase. 
E)  reverse transcriptase. 
A)  DNase. 
B)  DNA polymerase. 
C)  RNA primase. 
D)  RNA polymerase. 
E)  reverse transcriptase.

Question 10

A "5 ′ cap":

Accepted Answer

A)  prevents translation. 
B)  prevents the binding of ribosomes. 
C)  marks the mRNA for degradation. 
D)  is added to mRNA but not pre-mRNA. 
E)  protects mRNA from degradation. 
A)  prevents translation. 
B)  prevents the binding of ribosomes. 
C)  marks the mRNA for degradation. 
D)  is added to mRNA but not pre-mRNA. 
E)  protects mRNA from degradation.

Question 11

Introns in pre-mRNA:

Accepted Answer

A)  code for specific protein domains. 
B)  are spliced out of the message. 
C)  move within the mRNA, giving rise to new exon combinations. 
D)  protect pre-mRNA from enzyme degradation. 
E)  code for important amino acid sequences. 
A)  code for specific protein domains. 
B)  are spliced out of the message. 
C)  move within the mRNA, giving rise to new exon combinations. 
D)  protect pre-mRNA from enzyme degradation. 
E)  code for important amino acid sequences.

Question 12

A grouping of three nucleotides code for one amino acid. 
__________________

Accepted Answer

A) True 
 B)False

Question 13

During translocation, the movement of the ribosome repositions the tRNA linked to the growing polypeptide chain to the ____ site, thereby vacating the ____ site for the arrival of a new amino-acyl tRNA.

Accepted Answer

A)  A; P 
B)  P; A 
C)  initiation; termination 
D)  large ribosomal subunit; small ribosomal subunit 
E)  small ribosomal subunit; large ribosomal subunit 
A)  A; P 
B)  P; A 
C)  initiation; termination 
D)  large ribosomal subunit; small ribosomal subunit 
E)  small ribosomal subunit; large ribosomal subunit

Question 14

List the main steps involved in converting pre-mRNA to mRNA. Explain the purpose of each step.

Accepted Answer

1 Addition of a 5'cap: allows ribosome b

Question 15

RNA is ____ and contains the nitrogenous base ____, which is absent in DNA.

Accepted Answer

A)  single-stranded; thymine 
B)  double-stranded; uracil 
C)  single-stranded; uracil 
D)  double-stranded; thymine 
E)  single-stranded; cytosine 
A)  single-stranded; thymine 
B)  double-stranded; uracil 
C)  single-stranded; uracil 
D)  double-stranded; thymine 
E)  single-stranded; cytosine

Question 16

Figure 13-1   What conclusion was associated with mutant strain III in the accompanying figure?

Accepted Answer

A)  It contained all the enzymes needed for normal metabolism. 
B)  It was missing all the enzymes for metabolism of amino acids. 
C)  It was missing the enzyme that catalyzes the conversion of citrulline to arginine. 
D)  It was missing the enzyme that catalyzes the conversion of ornithine to citrulline. 
E)  It was missing the first enzyme in the arginine metabolic pathway. 
A)  It contained all the enzymes needed for normal metabolism. 
B)  It was missing all the enzymes for metabolism of amino acids. 
C)  It was missing the enzyme that catalyzes the conversion of citrulline to arginine. 
D)  It was missing the enzyme that catalyzes the conversion of ornithine to citrulline. 
E)  It was missing the first enzyme in the arginine metabolic pathway.

Question 17

One of the mRNA codons specifying the amino acid leucine is 5 ′ -CUA-3 ′ . Its corresponding anticodon is:

Accepted Answer

A)  5 ′ -GAT-3 ′ . 
B)  3 ′ -AUC-5 ′ . 
C)  3 ′ -GAU-5 ′ . 
D)  3 ′ -GAT-5 ′ . 
E)  5 ′ -GAU-3 ′ . 
A)  5 ′ -GAT-3 ′ . 
B)  3 ′ -AUC-5 ′ . 
C)  3 ′ -GAU-5 ′ . 
D)  3 ′ -GAT-5 ′ . 
E)  5 ′ -GAU-3 ′ .

Question 18

A mutation that replaces one amino acid in a protein with another is called a ____ mutation.

Accepted Answer

A)  frameshift 
B)  recombinant 
C)  nonsense 
D)  missense 
E)  neutral 
A)  frameshift 
B)  recombinant 
C)  nonsense 
D)  missense 
E)  neutral

Question 19

Beadle and Tatum irradiated Neurospora and initially grew the mutant strains on complete medium. How were they able to determine the type of mutation for each strain?

Accepted Answer

A)  By growing the mold on a complete medium with extra vitamins and nutrients 
B)  By growing the mold on minimal media supplemented with different combinations of amino acids and vitamins 
C)  By growing the mold in its diploid form to see which traits were masked 
D)  By comparing Neurospora to other species of mold 
E)  By observing the marked differences in morphology between the different strains 
A)  By growing the mold on a complete medium with extra vitamins and nutrients 
B)  By growing the mold on minimal media supplemented with different combinations of amino acids and vitamins 
C)  By growing the mold in its diploid form to see which traits were masked 
D)  By comparing Neurospora to other species of mold 
E)  By observing the marked differences in morphology between the different strains

Question 20

The poly-A tail is thought to facilitate the export of mRNA from the nucleus. 
__________________

Accepted Answer

A) True 
 B)False

Exam 13: Gene Expression

RNA interference i s a process by which noncoding RNA molecules regulate gene expression.

How does the first nucleotide at the 5 ′ end of a new mRNA chain differ from the other nucleotides in the chain?

Mobile genetic elements, such as transposons and retrotransposons, are significant because:

The total number of different three-base combinations of the four nucleic acid bases is:

tRNA molecules are able to act as adapters between amino acids and mRNA during translation because:

RNA synthesis is also known as:

Translation is initiated at the ____.

Transcription and translation occur simultaneously in prokaryotes. Why can't this process take place in eukaryotes? What disadvantage results from such linking in prokaryotes?

Figure 13-3 Refer to the accompanying figure. The component labeled as B is:

A "5 ′ cap":

Introns in pre-mRNA:

A grouping of three nucleotides code for one amino acid. __________________

During translocation, the movement of the ribosome repositions the tRNA linked to the growing polypeptide chain to the ____ site, thereby vacating the ____ site for the arrival of a new amino-acyl tRNA.

List the main steps involved in converting pre-mRNA to mRNA. Explain the purpose of each step.

RNA is ____ and contains the nitrogenous base ____, which is absent in DNA.

Figure 13-1 What conclusion was associated with mutant strain III in the accompanying figure?

One of the mRNA codons specifying the amino acid leucine is 5 ′ -CUA-3 ′ . Its corresponding anticodon is:

A mutation that replaces one amino acid in a protein with another is called a ____ mutation.

Beadle and Tatum irradiated Neurospora and initially grew the mutant strains on complete medium. How were they able to determine the type of mutation for each strain?

The poly-A tail is thought to facilitate the export of mRNA from the nucleus. __________________

A View of Life

Atoms and Molecules the Chemical Basis of Life

The Chemistry of Life Organic Compounds

Organization of the Cell

Biological Membranes

Cell Communication

Energy and Metabolism

How Cells Make Atp Energy-Releasing Pathways

Photosynthesis Capturing Light Energy

Chromosomes, Mitosis, and Meiosis

The Basic Principles of Heredity

Dna the Carrier of Genetic Information

Gene Regulation

Dna Technology and Genomics

Human Genetics and the Human Genome

Developmental Genetics

Introduction to Darwinian Evolution

Evolutionary Change in Populations

Speciation and Macroevolution

The Origin and Evolutionary History of Life

The Evolution of Primates

Understanding Diversity Systematics

Viruses and Subviral Agents

Bacteria and Archaea

Protists

Seedless Plants

Seed Plants

The Fungi

An Introduction to Animal Diversity

Sponges, Cnidarians, Ctenophores, and Protostomes

The Deuterostomes

Plant Structure Growth and Development

Leaf Structure and Function

Stem Structure and Transport

Roots and Mineral Nutrition

Reproduction in Flowering Plants

Plant Developmental Responses to External and Internal Signals

Animal Structure and Function an Introduction

Protection Support and Movement

Neural Signaling

Neural Regulation

Sensory Systems

Internal Transport

The Immune System Internal Defense

Gas Exchange

Processing Food and Nutrition

Osmoregulation and Disposal of Metabolic Wastes

Endocrine Regulation

Reproduction

Animal Development

Animal Behavior

Introduction to Ecology Population Ecology

Community Ecology

Ecosystems and the Biosphere

Ecology and the Geography of Life

Biological Diversity and Conservation Biology

Filters

During translocation, the movement of the ribosome repositions the tRNA linked to the growing polypeptide chain to the site, thereby vacating the site for the arrival of a new amino-acyl tRNA.

RNA is and contains the nitrogenous base , which is absent in DNA.