MOLECULAR DIAGNOSTICS CHAPTER
1-16 EXAM QUESTIONS WITH
COMPLETE ANSWERS
An exonuclease will catalyze what type of reaction? - ANSWER-Dissociation of
phosphodiester bonds at the ends of DNA molecules
What reactions are catalyzed by DNA methyltransferase? - ANSWER-Addition of
methyl groups to nitrogen bases
The purpose of ligase is to what? - ANSWER-Paste 2 ends of DNA together
What is the fertility factor (F) observed by Hayes and Lederberg? - ANSWER-A
plasmid
Avery, MacLeod, and McCarty identified the nature of Griffith's transforming factor in
an experiment where it was destroyed by what treatment? - ANSWER-
Deoxyribonuclease
The movement of DNA from one bacterium to another through the activity of
bacteriophages is called what? - ANSWER-Transduction
In sexual recombination, new combinations of genes are created by what process? -
ANSWER-Crossing over
Recombination between a plasmid and the cell chromosome will result in what? -
ANSWER-Stable integration of plasmid genes into the chromosome
In an RNA molecule, adenine always base-pairs with what? - ANSWER-Uracil
RNA and DNA are structurally similar because they both? - ANSWER-Are polymers
of 4 different nucleotide bases
RNA is degraded by? - ANSWER-Ribonucleases
The large ribosome subunit in prokaryotes consists of ribosomal proteins and what?
- ANSWER-23S rRNA and 5S rRNA
Transfer RNA is different from other types of RNA because transfer RNA has what? -
ANSWER-Anticodons
Synthesis of RNA guided by a DNA template is? - ANSWER-Transcription
Synthesis of DNA guided by a RNA template is? - ANSWER-Reverse transcription
In transcription, what is the starting material, the ending material, and the major
enzyme that catalyzes the process? - ANSWER-DNA, RNA, RNA polymerase
,Which enzymes performs transcription in bacteria? - ANSWER-DNA-dependent
RNA polymerase
The RNA polymerase holoenzyme consists of which subunits? - ANSWER-a2, B, B'o
Which component of RNA polymerase is responsible for initiating transcription at the
correct site? - ANSWER-o
What is required for termination of transcription in bacteria? - ANSWER-Rho
What is involved in termination of transcription in eukaryotes? - ANSWER-Poly A
signal
Which types of RNA is directly involved in removing introns from RNA in eukaryotes?
- ANSWER-Small nuclear
What is the secondary structure of transfer RNA? - ANSWER-Cruciform, or inverted
L
The loop of transfer RNA that interacts with the codon on mRNA in translation is
called? - ANSWER-Anticodon loop
DNA sequences that are involved in the regulation of gene expression are called? -
ANSWER-Cis factors
What is the binding site for the repressor protein of the lactose operon? - ANSWER-
Operator
What would prevent transcription of the lactose operon? - ANSWER-Loss of
promotor
What is a cis factor of the lactose operon? - ANSWER-Operator
In the lactose operon, which configurations would result in gene expression? -
ANSWER-Promotor+, Operator+, Repressor-, no inducer present
Multiple products are generated from the same gene by what mechanism? -
ANSWER-Alternative splicing
Thalassemias arise from changes in what part of the beta-globin gene? - ANSWER-
Splice recognition unit
When gene expression is regulated by mechanisms other than the interaction of cis
elements and trans factors, the regulation is called what? - ANSWER-Epigenetics
Genomic imprinting is accomplished primarily through what? - ANSWER-Methylation
The most frequently methylated base in vertebrates is what? - ANSWER-Cytosine
,MicroRNAs, short endogenous RNA, perform what function in the eukaryotic cell? -
ANSWER-Repressing gene expression
What mechanism may explain the difference in symptoms in Prader-Willi and
Angelman syndromes? - ANSWER-Genomic imprinting
Alteration of the nucleotide sequence of RNA after transcription is called? -
ANSWER-RNA editing
Describes the general structure of an amino acid. - ANSWER-Central carbon with
carboxyl group, amino group, hydrogen, and a side chain
The chemical nature of alanine, leucine, phenylalanine, and tryptophan is described
as what? - ANSWER-Non polar
Which amino acid has a nonpolar R group? - ANSWER-Valine
At physiological pH, amino acids are what? - ANSWER-Zwitterions
What chemical group is found at the beginning of peptide chains? - ANSWER-Amine
What chemical group is found at the end of peptide chains? - ANSWER-Carboxyl
The sequence of amino acids in a protein constitutes which level of protein
structure? - ANSWER-Primary
Alpha helices and beta-pleated sheets are what level of protein structure? -
ANSWER-Secondary
A protein that has lost its tertiary structure is called what? - ANSWER-Denatured
Protein structure characterized by the combination of different proteins that all
together are required for protein function is which level of protein structure? -
ANSWER-Quaternary
Denaturation of a protein results in what effect? - ANSWER-Loss of tertiary structure
The fundamental physical and functional unit of inheritance that encodes a functional
product is what? - ANSWER-gene
A codon consists of a sequence of how many nucleotides? - ANSWER-3
In translation, what is the starting material, the ending material, and the major
enzyme that catalyzes the process? - ANSWER-RNA, protein, peptidyl transferase
In early experiments, a polymer of uracil, UUUUUUUU..., translated into a peptide
comprising only phenylalanine amino acids. What did this observation demonstrate?
- ANSWER-UUU codes for phenylalanine
The process of protein synthesis is also called what? - ANSWER-Translation
, The set of nucleotides in mRNA that encode one amino acid is called a(n) what? -
ANSWER-Codon
All but two amino acids are encoded by more than one codon, thus making the
genetic code what? - ANSWER-Redundant
The codons that do not code for an amino acid and terminate protein synthesis are
what kind of codon? - ANSWER-Nonsense
What enzymes are important for faithful translation of genetic information from RNA
to protein? - ANSWER-Amino-acyl tRNA synthetase
The start codon for synthesis of most proteins is what? - ANSWER-AUG
The enzyme that bonds two amino acids together in protein synthesis is what? -
ANSWER-Peptidyl transferase
What amino acid is used to initiate most proteins in eukaryotes? - ANSWER-
Methionine
A glycoprotein contains what attached after translation? - ANSWER-Sugar moieties
Specialized proteins that bind to the large ribosomal subunit and protect the
hydrophobic regions of growing polypeptides are called what? - ANSWER-Molecular
chaperones
In the ribosome, the growing peptide moves from site to site in what direction? -
ANSWER-A to P to E
Hydrolysis of the finished polypeptide from the final tRNA by release factors would
occur at which of the following codons? - ANSWER-UGA
ER stress stops protein synthesis in response to what? - ANSWER-Unfolded
proteins
The collection of proteins produced by a genome is called the what? - ANSWER-
Proteome
Which whole blood fraction is the most abundant source of genomic DNA? -
ANSWER-Buffy Coat
Which specimen will yield the best DNA preparation? - ANSWER-Fresh Blood
What is the first step in DNA isolation from cells in a clinical sample? - ANSWER-
Lysis of cells
Phenol/chloroform and an aqueous solution will form what type of mixture? -
ANSWER-Emulsion
1-16 EXAM QUESTIONS WITH
COMPLETE ANSWERS
An exonuclease will catalyze what type of reaction? - ANSWER-Dissociation of
phosphodiester bonds at the ends of DNA molecules
What reactions are catalyzed by DNA methyltransferase? - ANSWER-Addition of
methyl groups to nitrogen bases
The purpose of ligase is to what? - ANSWER-Paste 2 ends of DNA together
What is the fertility factor (F) observed by Hayes and Lederberg? - ANSWER-A
plasmid
Avery, MacLeod, and McCarty identified the nature of Griffith's transforming factor in
an experiment where it was destroyed by what treatment? - ANSWER-
Deoxyribonuclease
The movement of DNA from one bacterium to another through the activity of
bacteriophages is called what? - ANSWER-Transduction
In sexual recombination, new combinations of genes are created by what process? -
ANSWER-Crossing over
Recombination between a plasmid and the cell chromosome will result in what? -
ANSWER-Stable integration of plasmid genes into the chromosome
In an RNA molecule, adenine always base-pairs with what? - ANSWER-Uracil
RNA and DNA are structurally similar because they both? - ANSWER-Are polymers
of 4 different nucleotide bases
RNA is degraded by? - ANSWER-Ribonucleases
The large ribosome subunit in prokaryotes consists of ribosomal proteins and what?
- ANSWER-23S rRNA and 5S rRNA
Transfer RNA is different from other types of RNA because transfer RNA has what? -
ANSWER-Anticodons
Synthesis of RNA guided by a DNA template is? - ANSWER-Transcription
Synthesis of DNA guided by a RNA template is? - ANSWER-Reverse transcription
In transcription, what is the starting material, the ending material, and the major
enzyme that catalyzes the process? - ANSWER-DNA, RNA, RNA polymerase
,Which enzymes performs transcription in bacteria? - ANSWER-DNA-dependent
RNA polymerase
The RNA polymerase holoenzyme consists of which subunits? - ANSWER-a2, B, B'o
Which component of RNA polymerase is responsible for initiating transcription at the
correct site? - ANSWER-o
What is required for termination of transcription in bacteria? - ANSWER-Rho
What is involved in termination of transcription in eukaryotes? - ANSWER-Poly A
signal
Which types of RNA is directly involved in removing introns from RNA in eukaryotes?
- ANSWER-Small nuclear
What is the secondary structure of transfer RNA? - ANSWER-Cruciform, or inverted
L
The loop of transfer RNA that interacts with the codon on mRNA in translation is
called? - ANSWER-Anticodon loop
DNA sequences that are involved in the regulation of gene expression are called? -
ANSWER-Cis factors
What is the binding site for the repressor protein of the lactose operon? - ANSWER-
Operator
What would prevent transcription of the lactose operon? - ANSWER-Loss of
promotor
What is a cis factor of the lactose operon? - ANSWER-Operator
In the lactose operon, which configurations would result in gene expression? -
ANSWER-Promotor+, Operator+, Repressor-, no inducer present
Multiple products are generated from the same gene by what mechanism? -
ANSWER-Alternative splicing
Thalassemias arise from changes in what part of the beta-globin gene? - ANSWER-
Splice recognition unit
When gene expression is regulated by mechanisms other than the interaction of cis
elements and trans factors, the regulation is called what? - ANSWER-Epigenetics
Genomic imprinting is accomplished primarily through what? - ANSWER-Methylation
The most frequently methylated base in vertebrates is what? - ANSWER-Cytosine
,MicroRNAs, short endogenous RNA, perform what function in the eukaryotic cell? -
ANSWER-Repressing gene expression
What mechanism may explain the difference in symptoms in Prader-Willi and
Angelman syndromes? - ANSWER-Genomic imprinting
Alteration of the nucleotide sequence of RNA after transcription is called? -
ANSWER-RNA editing
Describes the general structure of an amino acid. - ANSWER-Central carbon with
carboxyl group, amino group, hydrogen, and a side chain
The chemical nature of alanine, leucine, phenylalanine, and tryptophan is described
as what? - ANSWER-Non polar
Which amino acid has a nonpolar R group? - ANSWER-Valine
At physiological pH, amino acids are what? - ANSWER-Zwitterions
What chemical group is found at the beginning of peptide chains? - ANSWER-Amine
What chemical group is found at the end of peptide chains? - ANSWER-Carboxyl
The sequence of amino acids in a protein constitutes which level of protein
structure? - ANSWER-Primary
Alpha helices and beta-pleated sheets are what level of protein structure? -
ANSWER-Secondary
A protein that has lost its tertiary structure is called what? - ANSWER-Denatured
Protein structure characterized by the combination of different proteins that all
together are required for protein function is which level of protein structure? -
ANSWER-Quaternary
Denaturation of a protein results in what effect? - ANSWER-Loss of tertiary structure
The fundamental physical and functional unit of inheritance that encodes a functional
product is what? - ANSWER-gene
A codon consists of a sequence of how many nucleotides? - ANSWER-3
In translation, what is the starting material, the ending material, and the major
enzyme that catalyzes the process? - ANSWER-RNA, protein, peptidyl transferase
In early experiments, a polymer of uracil, UUUUUUUU..., translated into a peptide
comprising only phenylalanine amino acids. What did this observation demonstrate?
- ANSWER-UUU codes for phenylalanine
The process of protein synthesis is also called what? - ANSWER-Translation
, The set of nucleotides in mRNA that encode one amino acid is called a(n) what? -
ANSWER-Codon
All but two amino acids are encoded by more than one codon, thus making the
genetic code what? - ANSWER-Redundant
The codons that do not code for an amino acid and terminate protein synthesis are
what kind of codon? - ANSWER-Nonsense
What enzymes are important for faithful translation of genetic information from RNA
to protein? - ANSWER-Amino-acyl tRNA synthetase
The start codon for synthesis of most proteins is what? - ANSWER-AUG
The enzyme that bonds two amino acids together in protein synthesis is what? -
ANSWER-Peptidyl transferase
What amino acid is used to initiate most proteins in eukaryotes? - ANSWER-
Methionine
A glycoprotein contains what attached after translation? - ANSWER-Sugar moieties
Specialized proteins that bind to the large ribosomal subunit and protect the
hydrophobic regions of growing polypeptides are called what? - ANSWER-Molecular
chaperones
In the ribosome, the growing peptide moves from site to site in what direction? -
ANSWER-A to P to E
Hydrolysis of the finished polypeptide from the final tRNA by release factors would
occur at which of the following codons? - ANSWER-UGA
ER stress stops protein synthesis in response to what? - ANSWER-Unfolded
proteins
The collection of proteins produced by a genome is called the what? - ANSWER-
Proteome
Which whole blood fraction is the most abundant source of genomic DNA? -
ANSWER-Buffy Coat
Which specimen will yield the best DNA preparation? - ANSWER-Fresh Blood
What is the first step in DNA isolation from cells in a clinical sample? - ANSWER-
Lysis of cells
Phenol/chloroform and an aqueous solution will form what type of mixture? -
ANSWER-Emulsion
