Question 1

DNA probes are used to find regions of complementary DNA.

Accepted Answer

A) True 
 B)False  True

Question 2

The Ti plasmid is used as a vector to transfer DNA into

Accepted Answer

A)  viruses. 
B)  bacteria. 
C)  plant cells. 
D)  animal cells. 
E)  protozoa. 
A)  viruses. 
B)  bacteria. 
C)  plant cells. 
D)  animal cells. 
E)  protozoa. C

Question 3

Mitochondrial DNA (mtDNA) in humans

Accepted Answer

A)  is always donated to the offspring from both parents. 
B)  can be used to identify related people. 
C)  can be isolated only from intact embryos. 
D)  can be used to establish paternity. 
E)  is linear, single-stranded DNA. 
A)  is always donated to the offspring from both parents. 
B)  can be used to identify related people. 
C)  can be isolated only from intact embryos. 
D)  can be used to establish paternity. 
E)  is linear, single-stranded DNA. B

Question 4

The energy to separate fragments during agarose gel electrophoresis is supplied by

Accepted Answer

A)  gravity. 
B)  electricity. 
C)  active transport. 
D)  agarosis. 
E)  buffers. 
A)  gravity. 
B)  electricity. 
C)  active transport. 
D)  agarosis. 
E)  buffers.

Question 5

When detecting microorganisms, a probe that hybridizes to sequences on ribosomal RNA (rRNA) is generally used. This is because

Accepted Answer

A)  not all bacteria have DNA but they all have large quantities of ribosomal RNA. 
B)  rRNA is in the cytoplasm so is easy to detect but DNA is in the nucleus so is harder to detect. 
C)  cells that are dividing can have thousands of copies of rRNA, increasing the technique's sensitivity. 
D)  RNA is a single-stranded molecule but DNA is a triple helix and must be denatured. 
E)  These are all reasons that rRNA is targeted. 
A)  not all bacteria have DNA but they all have large quantities of ribosomal RNA. 
B)  rRNA is in the cytoplasm so is easy to detect but DNA is in the nucleus so is harder to detect. 
C)  cells that are dividing can have thousands of copies of rRNA, increasing the technique's sensitivity. 
D)  RNA is a single-stranded molecule but DNA is a triple helix and must be denatured. 
E)  These are all reasons that rRNA is targeted.

Question 6

A common way to identify the E. coli that carries the desired recombinant DNA is by using a(n)

Accepted Answer

A)  vector. 
B)  probe. 
C)  host. 
D)  plasmid. 
E)  antibiotic. 
A)  vector. 
B)  probe. 
C)  host. 
D)  plasmid. 
E)  antibiotic.

Question 7

The DNA polymerase used in PCR comes from the bacterium thermophile Thermus aquaticus, and is called Taq polymerase. Why is this enzyme used, and not a DNA polymerase from an organism such as E. coli?

Accepted Answer

A)  The DNA synthesis step of the PCR cycle occurs at 95ᵒC; Taq polymerase is from a bacterium that grows in high temperatures and can function at this temperature, while DNA polymerase from a mesophile such as E. coli would be denatured at this temperature. 
B)  The DNA synthesis step of the PCR cycle occurs at 72ᵒC; Taq polymerase can function at this temperature, while DNA polymerase from a mesophile such as E. coli requires significantly higher temperatures in order to function correctly. 
C)  E. coli is an RNA organism and therefore depends on RNA polymerase for its replication cycle; it is not possible to obtain DNA polymerase from this bacterium. 
D)  The DNA synthesis step of the PCR cycle occurs at 72ᵒC; Taq polymerase is from a bacterium that grows in high temperatures and can function at this temperature, while DNA polymerase from a mesophile such as E. coli would be denatured at this temperature. 
E)  DNA polymerase from Thermus aquaticus is a very active enzyme. It is able to synthesize DNA at a faster rate than any other known DNA polymerase which is important because the key to successful PCR is a speedy reaction. 
A)  The DNA synthesis step of the PCR cycle occurs at 95ᵒC; Taq polymerase is from a bacterium that grows in high temperatures and can function at this temperature, while DNA polymerase from a mesophile such as E. coli would be denatured at this temperature. 
B)  The DNA synthesis step of the PCR cycle occurs at 72ᵒC; Taq polymerase can function at this temperature, while DNA polymerase from a mesophile such as E. coli requires significantly higher temperatures in order to function correctly. 
C)  E. coli is an RNA organism and therefore depends on RNA polymerase for its replication cycle; it is not possible to obtain DNA polymerase from this bacterium. 
D)  The DNA synthesis step of the PCR cycle occurs at 72ᵒC; Taq polymerase is from a bacterium that grows in high temperatures and can function at this temperature, while DNA polymerase from a mesophile such as E. coli would be denatured at this temperature. 
E)  DNA polymerase from Thermus aquaticus is a very active enzyme. It is able to synthesize DNA at a faster rate than any other known DNA polymerase which is important because the key to successful PCR is a speedy reaction.

Question 8

PCR produces

Accepted Answer

A)  DNA fragments of all possible sizes. 
B)  DNA fragments that are one nucleotide larger than the next fragment. 
C)  DNA fragments of a particular size. 
D)  protein fragments of all possible sizes. 
E)  DNA fragments that are three nucleotides smaller than the previous fragment. 
A)  DNA fragments of all possible sizes. 
B)  DNA fragments that are one nucleotide larger than the next fragment. 
C)  DNA fragments of a particular size. 
D)  protein fragments of all possible sizes. 
E)  DNA fragments that are three nucleotides smaller than the previous fragment.

Question 9

The polymerase chain reaction is used to

Accepted Answer

A)  amplify mRNA. 
B)  amplify certain sections of DNA. 
C)  produce proteins. 
D)  produce long polymers of carbohydrates to be used in electrophoresis. 
E)  produce long polymers of amino acids to be used in electrophoresis. 
A)  amplify mRNA. 
B)  amplify certain sections of DNA. 
C)  produce proteins. 
D)  produce long polymers of carbohydrates to be used in electrophoresis. 
E)  produce long polymers of amino acids to be used in electrophoresis.

Question 10

Tuberculosis (TB) is caused by the acid-fast bacterium Mycobacterium tuberculosis. Although most TB cases affect the lungs (pulmonary TB), some infections occur in other body sites (extrapulmonary TB). Among these cases, lymph node tuberculosis (LNTB) is the most common. Diagnosis of LNTB by conventional methods (staining, biochemical tests) has limitations—for example, formaldehyde preservation of tissue biopsies interferes with the acid-fast stain, leading to underdiagnosis or misdiagnosis. Now fluorescent in situ hybridization (FISH) is being used to diagnose extrapulmonary TB.

-When a tissue sample such as lymph node tissue is to be analyzed by FISH, it must first be treated with chemicals. Which of the following is NOT a reason that this step is needed?

Accepted Answer

A)  To maintain cell shape. 
B)  To inactivate enzymes that might otherwise degrade the nucleic acid of the cells. 
C)  To make the cells more permeable so that the labeled probe can easily enter. 
D)  To inactivate enzymes that might otherwise degrade the nucleic acid of the cells AND to maintain cell shape. 
E)  To break down the cellulose walls of the tissue so that the probes can enter those cells. 
A)  To maintain cell shape. 
B)  To inactivate enzymes that might otherwise degrade the nucleic acid of the cells. 
C)  To make the cells more permeable so that the labeled probe can easily enter. 
D)  To inactivate enzymes that might otherwise degrade the nucleic acid of the cells AND to maintain cell shape. 
E)  To break down the cellulose walls of the tissue so that the probes can enter those cells.

Question 11

Bacteria use CRISPR for gene editing.

Accepted Answer

A) True 
 B)False

Question 12

Which nitrogenous base does the dideoxynucleotide ddNTP contain?

Accepted Answer

A)  Adenine 
B)  Thymine 
C)  Cytosine 
D)  Guanine 
E)  A, T, G or C 
A)  Adenine 
B)  Thymine 
C)  Cytosine 
D)  Guanine 
E)  A, T, G or C

Question 13

Double-stranded DNA will separate into two strands when exposed to

Accepted Answer

A)  high temperature AND low pH 
B)  high pH AND low salt 
C)  low temperature AND high salt 
D)  low salt AND low pH 
E)  high temperature AND high pH. 
A)  high temperature AND low pH 
B)  high pH AND low salt 
C)  low temperature AND high salt 
D)  low salt AND low pH 
E)  high temperature AND high pH.

Question 14

PCR generates a DNA fragment of a distinct size even when the whole viral chromosome is used as a template. What determines the boundaries of the amplified fragment?

Accepted Answer

A)  The concentration of one particular deoxynucleotide in the reaction. 
B)  The length of time of the elongation step in each cycle. 
C)  The position of a termination sequence, which causes the Taq polymerase to fall off the template. 
D)  The sites on the template DNA to which the specific primers used in the reaction anneal. 
E)  The temperature at which the elongation step in each cycle is carried out. 
A)  The concentration of one particular deoxynucleotide in the reaction. 
B)  The length of time of the elongation step in each cycle. 
C)  The position of a termination sequence, which causes the Taq polymerase to fall off the template. 
D)  The sites on the template DNA to which the specific primers used in the reaction anneal. 
E)  The temperature at which the elongation step in each cycle is carried out.

Question 15

In a recent research article describing the use of FISH to detect LNTB, the authors noted that they used probes that were only 20 base pairs (bp) in length rather than the conventional 100 bp-500 bp. Given what you know about acid-fast bacteria, why do you think they took this approach?

Accepted Answer

A)  The nature of the Mycobacterial cytoplasmic membrane likely makes is difficult for larger probes to enter the cell. 
B)  The nature of the Mycobacterial capsule likely makes is difficult for larger probes to enter the cell. 
C)  The nature of the Mycobacterial cell wall likely makes is difficult for larger probes to enter the cell. 
D)  Mycobacteria have a lipopolysaccharide outer membrane through which larger probes cannot enter. 
E)  Mycobacteria have smaller ribosomes than any other bacteria and the probes are targeted at rRNA. 
A)  The nature of the Mycobacterial cytoplasmic membrane likely makes is difficult for larger probes to enter the cell. 
B)  The nature of the Mycobacterial capsule likely makes is difficult for larger probes to enter the cell. 
C)  The nature of the Mycobacterial cell wall likely makes is difficult for larger probes to enter the cell. 
D)  Mycobacteria have a lipopolysaccharide outer membrane through which larger probes cannot enter. 
E)  Mycobacteria have smaller ribosomes than any other bacteria and the probes are targeted at rRNA.

Question 16

When a vector that uses the lacZ gene as a second marker is used in a cloning experiment, bacteria that contain the recombinant DNA will give rise to

Accepted Answer

A)  red colonies. 
B)  white colonies. 
C)  blue colonies. 
D)  cream colonies. 
E)  All of the answer choices are correct. 
A)  red colonies. 
B)  white colonies. 
C)  blue colonies. 
D)  cream colonies. 
E)  All of the answer choices are correct.

Question 17

Why must an agarose gel be placed in a buffer solution for DNA gel electrophoresis?

Accepted Answer

A)  Ions in the buffer conduct the electric current needed to move the DNA fragments in the gel matrix. 
B)  The DNA fragments will disintegrate unless there is a buffer present to prevent this from happening. 
C)  Even distilled, autoclaved water has a high number of DNases in it that would destroy the DNA. 
D)  The buffer contains phosphates, and the DNA fragments must be phosphorylated before they move in agarose. 
E)  DNA cannot be detected unless buffer is added to the system; the buffer colors the DNA fragments for visualization. 
A)  Ions in the buffer conduct the electric current needed to move the DNA fragments in the gel matrix. 
B)  The DNA fragments will disintegrate unless there is a buffer present to prevent this from happening. 
C)  Even distilled, autoclaved water has a high number of DNases in it that would destroy the DNA. 
D)  The buffer contains phosphates, and the DNA fragments must be phosphorylated before they move in agarose. 
E)  DNA cannot be detected unless buffer is added to the system; the buffer colors the DNA fragments for visualization.

Question 18

The sequence of cDNA synthesized from an mRNA template with the sequence AUGGUA would be ________. This cDNA probe would hybridize to gene chip DNA with the sequence ________.

Accepted Answer

A)  UACCAU; ATGGTA 
B)  TACCAT; AUGGUA 
C)  AUGGUA; AUGGUA 
D)  TACCAT; ATGGTA 
E)  AUGGUA; TACCAT 
A)  UACCAU; ATGGTA 
B)  TACCAT; AUGGUA 
C)  AUGGUA; AUGGUA 
D)  TACCAT; ATGGTA 
E)  AUGGUA; TACCAT

Question 19

FISH uses labeled probes to detect specific whole cells.

Accepted Answer

A) True 
 B)False

Question 20

Knowing the sequence of a genome is useful in

Accepted Answer

A)  identifying genetic alterations associated with disease AND studying evolutionary relationships. 
B)  studying evolutionary relationships AND determining protein sequences. 
C)  determining protein sequences AND identifying genetic alterations associated with disease. 
D)  determining protein sequences BUT not identifying genetic changes. 
E)  identifying genetic alterations associated with disease, studying evolutionary relationships, AND determining protein sequences. 
A)  identifying genetic alterations associated with disease AND studying evolutionary relationships. 
B)  studying evolutionary relationships AND determining protein sequences. 
C)  determining protein sequences AND identifying genetic alterations associated with disease. 
D)  determining protein sequences BUT not identifying genetic changes. 
E)  identifying genetic alterations associated with disease, studying evolutionary relationships, AND determining protein sequences.

Exam 9: Biotechnology

DNA probes are used to find regions of complementary DNA.

The Ti plasmid is used as a vector to transfer DNA into

Mitochondrial DNA (mtDNA) in humans

The energy to separate fragments during agarose gel electrophoresis is supplied by

When detecting microorganisms, a probe that hybridizes to sequences on ribosomal RNA (rRNA) is generally used. This is because

A common way to identify the E. coli that carries the desired recombinant DNA is by using a(n)

The DNA polymerase used in PCR comes from the bacterium thermophile Thermus aquaticus, and is called Taq polymerase. Why is this enzyme used, and not a DNA polymerase from an organism such as E. coli?

PCR produces

The polymerase chain reaction is used to

Bacteria use CRISPR for gene editing.

Which nitrogenous base does the dideoxynucleotide ddNTP contain?

Double-stranded DNA will separate into two strands when exposed to

PCR generates a DNA fragment of a distinct size even when the whole viral chromosome is used as a template. What determines the boundaries of the amplified fragment?

In a recent research article describing the use of FISH to detect LNTB, the authors noted that they used probes that were only 20 base pairs (bp) in length rather than the conventional 100 bp-500 bp. Given what you know about acid-fast bacteria, why do you think they took this approach?

When a vector that uses the lacZ gene as a second marker is used in a cloning experiment, bacteria that contain the recombinant DNA will give rise to

Why must an agarose gel be placed in a buffer solution for DNA gel electrophoresis?

The sequence of cDNA synthesized from an mRNA template with the sequence AUGGUA would be ________. This cDNA probe would hybridize to gene chip DNA with the sequence ________.

FISH uses labeled probes to detect specific whole cells.

Knowing the sequence of a genome is useful in

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Microbial Growth

Control of Microbial Growth

Microbial Metabolism: Fueling Cell Growth

The Blueprint of Life, from DNA to Protein

Bacterial Genetics

Identifying and Classifying Microorganisms

The Diversity of Bacteria and Archaea

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunological Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Blood and Lymphatic Infections

Nervous System Infections

Genitourinary Tract Infections

Microbial Ecology

Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Food Microbiology

Filters

The sequence of cDNA synthesized from an mRNA template with the sequence AUGGUA would be . This cDNA probe would hybridize to gene chip DNA with the sequence .