Micro Exam 3

A gene is ________.

the RNA product of a transcribed section of DNA

a three-nucleotide segment of DNA that code for an amino acid

a sequence of nucleotides in RNA that codes for a functional product

a sequence of nucleotides in DNA that codes for a functional product

any random segment of DNA

a sequence of nucleotides in DNA that codes for a functional product

Which of the following pairs is mismatched?

transposase – cuts DNA backbone, leaving "sticky ends"

RNA polymerase – makes a molecule of RNA from an RNA template

DNA gyrase – relaxes supercoiling in DNA ahead of the replication fork

DNA polymerase – makes a molecule of DNA from a DNA template

DNA ligase – joins segments of DNA

RNA polymerase – makes a molecule of RNA from an RNA template

It makes RNA from DNA

All are true except:

DNA replication proceeds in only one direction around the bacterial chromosome.

The lagging strand of DNA is started by an RNA primer.

Multiple replication forks are possible on a bacterial chromosome.

The leading strand of DNA is made continuously.

DNA polymerase joins nucleotides in one direction (5' to 3') only.

DNA replication proceeds in only one direction around the bacterial chromosome.

DNA is constructed of:

Two complementary strands of nucleotides bonded A—C and G—T.

A single strand of nucleotides with internal hydrogen bonding.

Two strands of identical nucleotides in a parallel configuration with hydrogen bonds between them.

Two strands of nucleotides running in an antiparallel configuration.

None of the answers is correct.

Two strands of nucleotides running in an antiparallel configuration.

Which of the following is NOT a product of transcription?

rRNA

a new strand of DNA

mRNA

tRNA

a new strand of DNA

The necessary ingredients for DNA synthesis can be mixed together in a test tube. The DNA polymerase is from Thermus aquaticus, and the template is from a human cell. The product of the DNA synthesis would be most similar to ________.

human DNA

a mixture of human and T. aquaticus DNA

T. aquaticus DNA

human RNA

T. aquaticus RNA

human DNA

If you knew the sequence of nucleotides within a gene, which one of the following could you determine with the most accuracy?

the quaternary structure of the protein

the secondary structure of the protein

the primary structure of the protein

the tertiary structure of the protein

The answer cannot be determined based on the information provided.

the primary structure of the protein

An enzyme that makes covalent bonds between Okazaki fragments in the lagging strand of DNA being replicated is

RNA polymerase.

SSBP.

DNA helicase.

DNA ligase

transposase.

DNA ligase

An enzyme that transcribes DNA to RNA is ________.

DNA helicase

DNA polymerase

RNA polymerase

DNA ligase

transposase

RNA polymerase

Protein synthesis in both eukaryotes and prokaryotes requires ________.

the use of codons to determine polypeptide sequences

the use of methionine as the "start" amino acid

snRNPS

exons

introns

the use of codons to determine polypeptide sequences

Which of the following enzymes unwinds the two strands of DNA so that they can be copied during replication?

Transposase

DNA polymerase

Helicase

DNA gyrase

helicase

Which of the following is a DNA strand complementary to CGA ATC AGC?

CGA ATC AGC

TAG GCT GAT

GCU UAG UCG

GCT TAG TCG

GCT TAG TCG

Open-reading frames are segments of DNA in which both start and stop codons are found.

True

False

True

Bacteria usually possess multiple chromosomes.

True

False

False

An enzyme produced in response to the presence of a substrate is called a(n)

inducible enzyme.

repressible enzyme.

promoter.

restriction enzyme.

operator.

inducible enzyme

According to the operon model, for the synthesis of an inducible gene to occur, the ________.

substrate must bind to the protein repressor

protein repressor must bind to the operator

end-product must not be in excess

protein repressor must not be synthesized

substrate must bind to the enzyme

substrate must bind to the protein repressor

Synthesis of a repressible is stopped by the ________.

substrate binding to the protein repressor

corepressor-repressor complex binding to the operator

corepressor binding to the operator

allosteric transition

the end product binding to the promoter

corepressor-repressor complex binding to the operator

The mechanism by which the presence of glucose inhibits the lac operon is

repression.

catabolite repression.

DNA polymerase.

induction.

translation.

catabolite repression

Which of the following statements concerning sugar utilization in E. coli is true?

During the lag time between glucose and lactose consumption, intracellular cAMP decreases.

When glucose is available, the level of cAMP in the E. coli is high.

Bacteria growing in a medium containing glucose and lactose will first consume the lactose.

Bacteria growing in glucose as the sole carbon source grow faster than on lactose.

Bacteria growing in glucose as the sole carbon source grow faster than on lactose

E. coli utilizes glucose more efficiently as an energy source than lactose; therefore, E. coli grows faster in glucose than in lactose.

DNA damage caused by ultraviolet radiation is ________.

repaired during transcription

never repaired

repaired by DNA replication

repaired during translation

repaired by excision

repaired by excision (removal of damaged or unwanted DNA)

Repair of damaged DNA, in some instances and mechanisms, might be viewed as a race between an endonuclease and

DNA polymerase.

methylase.

primase.

helicase.

DNA ligase.

methylase

The ozone layer of the Earth has been depleted to an extent by human release of certain chemicals. What type of mutation, caused by the induction of thymine dimer formation, is more likely to occur in organisms on Earth as a result of this problem?

nonsense mutation

silent mutation

missense mutation

frameshift mutation

frameshift mutation

Which of the following does NOT accurately apply to the Ames test?

The Ames test is based on the observation that reversions CANNOT occur in mutant bacteria.

The Ames test measures the reversion of histidine auxotrophs of Salmonella.

The test can be used to qualitatively test potential mutagens.

The test uses bacteria as mutagen, carcinogen indicators.

The Ames test is based on the observation that reversion CANNOT occur in mutant bacteria

The whole premise of the test is to look for chemicals that cause reversions to a previous phenotype. These reversions are due to changes in the DNA sequence.

Deleting or inserting one nucleotide pair in the middle of a gene is an example of which of the following?

Base substitution

Nonsense mutation

Frameshift mutation

Missense mutation

Frameshift mutation

Deletions or insertions result in a change in the reading frame of a gene (the three-nucleotide groupings for codons). Thus, they are termed frameshift mutations.

Harmful mutations often occur more frequently than beneficial mutations.

True

False

True

Both base substitution and frameshift mutations can result in the formation of premature stop codons.

True

False

True

Which of the following statements about bacteriocins is FALSE?

They cause food-poisoning symptoms.

The genes coding for them are on plasmids.

They can be used to identify certain bacteria.

Bacteriocins kill bacteria.

They cause food-poisoning symptoms

Culture 1: F⁺, leucine⁺, histidine⁺
Culture 2: F^-, leucine^-, histidine^-


In the table, what will be the result of conjugation between cultures 1 and 2 (reminder: F+ has a different meaning than Hfr)?

1 will remain the same; 2 will become F+, leu+, his+

1 will become F-, leu+, his+; 2 will become F+, leu-, his-

1 will remain the same; 2 will become F+ and recombination may occur

1 will become F-, leu-, his-; 2 will remain the same

1 will remain the same; 2 will become F+, leucine-, histidine-

1 will remain the same; 2 will become F+, leucine-, histidine-

Transformation is the transfer of DNA from a donor to a recipient cell

by crossing over.

by a bacteriophage.

by sexual reproduction.

by cell-to-cell contact.

as naked DNA in solution.

as naked DNA in solution

Gene transfer by conjugation differs from reproduction because ________.

conjugation transfers DNA vertically to new cells

conjugation copies RNA to make DNA

in conjugation DNA replicates

conjugation transcribes DNA to RNA

conjugation transfers DNA horizontally to nearby cells

conjugation transfers DNA horizontally to nearby cells

An enzyme that catalyzes the cutting and resealing of DNA that is translated from insertion sequences is called ________.

DNA polymerase

RNA polymerase

transposase

DNA helicase

DNA ligase

transposase

Transduction requires a(n) ________ to move DNA from one bacterial cell to another.

bacteriophage

F plasmid

transposase enzyme

naked DNA molecule

bacteriophage

If generalized transduction is underway, packaging a piece of DNA from an infected bacterial cell into a bacteriophage protein coat, what is the likely outcome?

A second bacterial cell infected by that transducing bacteriophage will acquire new DNA, carried by the phage from the original infected cell.

The infected bacterial cell will recover and survive, as the packaging of non-bacteriophage DNA into the protein coat produces nonfunctional virus particles.

Lysis of a newly infected cell as the transducing bacteriophage infects it and multiplies.

The virus particle formed in the transduction process can't correctly infect a new bacterial cell.

A second bacterial cell infected by that transducing bacteriophage will acquire new DNA, carried by the phage from the original infected cell.

Which of the following is a method of vertical gene transmission?

Cell division

Conjugation

Transformation

Transduction

cell division

Genetic recombination will always alter the genotype of a cell.

True

False

True

Cell-to-cell contact is required for transduction to occur.

True

False

False

Which of the following is an advantage of using E. coli to make a human gene product?

Endotoxin may be in the product.

Endotoxin may be in the product and it does not secrete most proteins.

Its genes are well known.

It does not secrete most proteins.

It cannot process introns.

Its genes are well known

Biotechnology involves the

use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistant crop plants.

use of microorganisms to make desired products and the use of animal cells to make vaccines.

use of animal cells to make vaccines.

development of disease-resistant crop plants.

use of microorganisms to make desired products.

use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistant crop plants

A population of bacterial cells carrying a desired plasmid is called a ________.

Southern blot

library

clone

vector

PCR

clone

Self-replicating DNA used to transmit DNA from one organism to another is a ________.

clone

library

Southern blot

PCR

vector

vector

The term biotechnology refers exclusively to the use of genetically engineered organisms to produce desired products.

True

False

false

The restriction enzyme EcoRI recognizes the sequence G↓AATTC and cut between G and A to yield sticky ends. Which of the following is true of DNA after it is treated with EcoRI?

All of the DNA will have blunt ends.

All of the DNA will be circular.

All of the DNA fragments will have single-stranded regions ending in AA.

Some of the DNA will have single-stranded regions ending in AA and others will end in G.

All of the DNA fragments will have single-stranded regions ending in G.

All of the DNA fragments will have single-stranded regions ending in AA

Which enzyme would cut this strand of DNA?
GCATGGATCCCAATGC

Enzyme Recognition HindIII A↓AGCTT TTCGA↑A

Enzyme Recognition Pst ICTGC↓G G↑ACGTC

Enzyme Recognition BamHI G↓GATCC CCCTAG↑G

Enzyme Recognition EcoRI G↓AATTC CTTAA↑G

Enzyme Recognition HaeIII GG↓CC CC↑GG

Enzyme Recognition
BamHI G↓GATCC
CCCTAG↑G

Which of the following places the steps in the PCR procedure in the correct order?
1) Incubate at 94°C to denature DNA strands;
2) Incubate at 72°C for DNA synthesis;
3) Incubate at 60°C for primer hybridization.

1, 2, 3

3; 1; 2

2; 1; 3

3, 2, 1

1, 3, 2

1, 3, 2

A source of heat-stable DNA polymerase is

Pseudomonas.

Saccharomyces cerevisiae.

Bacillus thuringiensis.

Agrobacterium tumefaciens.

Thermus aquaticus.

Thermus aquaticus

A restriction fragment is ________.

a segment of DNA which contain cutting site(s) for restriction enzymes

a segment of tRNA which contain cutting site(s) for restriction enzymes

a segment of mRNA which contain cutting site(s) for restriction enzymes

a gene

cDNA

a segment of DNA which contain cutting site(s) for restriction enzymes

One advantage of a viral vector over a plasmid vector is that the

the viral vector can accept larger pieces of DNA and the plasmid vector is circular.

viral vector can harbor a selection marker.

viral vector can accept a PCR fragment.

plasmid vector is circular.

viral vector can accept much larger pieces of DNA.

viral vector can accept much larger pieces of DNA

Which of the following is NOT a property of useful vectors?

They must have properties that allow their survival in the host cell.

They must be able to self-replicate.

They always contain only one gene.

They must be small enough to allow them to be manipulated prior to injection

They always contain only one gene

Vectors often contain more than one gene, including the gene of interest being introduced as well as a marker gene

Scientists use fluorescent proteins for various types of recombinant DNA procedures. You have a very small amount of the gene for a fluorescent protein. You'd like to make a fluorescent bacterium. Which of the following is the correct sequence of procedures that you would use?

Amplify the gene using PCR. Insert the gene into a plasmid vector. Transform the vector into the bacteria.

Transform the vector into the bacteria. Amplify the gene using PCR. Insert the gene into a plasmid vector.

Amplify the gene using PCR. Transform the vector into the bacteria. Insert the gene into a plasmid vector.

Insert the gene into a plasmid vector. Amplify the gene using PCR. Transform the vector into the bacteria.

Amplify the gene using PCR. Insert the gene into a plasmid vector. Transform the vector into the bacteria

You must amplify your fluorescent gene DNA before inserting it into a plasmid and expressing it in a bacterium

A shuttle vector is a plasmid that is used to move pieces of DNA among organisms such as bacterial, fungal and plant cells.

True

False

True

The reaction catalyzed by reverse transcriptase is

tRNA → mRNA.

mRNA → protein.

DNA → DNA.

DNA → mRNA.

mRNA → cDNA.

mRNA→ cDNA

The most important property of a DNA vector is

the size of the vector.

the fact that it contains a marker.

that the inserted genes that lack exons.

that it contains an ability to integrate into the chromosome.

its ability to replicate within the cell.

its ability to replicate within the cells

Place the steps of constructing a genomic library in order.
I. Digest phage with restriction enzyme.
II. Lyse cells of interest and precipitate DNA.
III. Introduce constructs via transformation into competent E. coli cells.
IV. Perform ligation reaction with genome fragments and phage.
V. Digest genomic DNA with restriction enzyme.

II, I, III, V, IV.

V, IV, I, III. II.

I, II, III, IV, V.

II, V, I, IV, III.

IV, II, III, I, V.

II, V, I, IV, III

Which of the following processes is not required in making cDNA?

Transcription

Translation

Reverse transcription

RNA processing to remove introns

Translation

Foreign DNA can be inserted into cells using a variety of methods. Which method involves the formation of microscopic pores in the cell's membrane?

transformation

heat shock

electroporation

protoplast fusion

electroporation

Microscopic pores in the cell membrane are formed by applying an electrical current. DNA can enter cells through these pores.

The disadvantage of genomic libraries over cDNA libraries is that genomic libraries contain introns in their DNA collections.

True

False

True

The following steps are used to make DNA fingerprints. What is the third step?

Collect DNA

Lyse cells

Perform electrophoresis

Add stain

Digest with a restriction enzyme

Digest with a restriction enzyme

If you have inserted a gene in the Ti plasmid, the next step in genetic engineering is

inserting the Ti plasmid into a plant cell.

transformation of an animal cell.

inserting the Ti plasmid into Agrobacterium.

splicing T DNA into a plasmid.

transformation of E. coli with Ti plasmid.

inserting the Ti plasmid into Agrobacterium

The Human Genome Project, which was completed in 2003, was focused on

identifying all of the genes in the human genome.

determining all of the proteins encoded by the human genome.

cloning all of the genes of the human genome.

finding a cure for all human genetic disorders.

determining the nucleotide sequence of the entire human genome.

determining the nucleotide sequence of the entire human genome

The field of proteomics concerns itself with

determining all of the proteins expressed by a cell.

synthesizing proteins from altered genetic sequences.

discovering the function of genes from a genetic sequence.

identifying an organism that makes improved enzymes.

identifying pathogens using RFLPs.

determining all of the proteins expr3essed by a cell

In the past, Pap test for cervical cancer used to involve microscopic examination of cervical cells for cancerous cells. A new, rapid diagnostic test, to detect human papilloma virus (HPV) DNA before cancer develops is done without microscopic exam. Of the steps for the Fast HPV test listed below. What is the second step?

The order is unimportant.

Add an RNA probe for HPV DNA.

Add enzyme substrate.

Lyse human cells.

Add enzyme-linked antibodies against DNA-RNA.

Add an RNA probe for HPV DNA.

Which of the following are used by the Centers for Disease Control and Prevention to track outbreaks of foodborne disease?

DNA fingerprints

Restriction fragment length polymorphisms (RFLP)

Reverse-transcriptase PCR (rtPCR)

DNA fingerprints and restriction fragment length polymorphisms

DNA fingerprints, restriction fragment length polymorphisms, and reverse-transcriptase PCR(rtPCR)

DNA fingerprints, restriction fragment length polymorphisms, and reverse-transcriptase PCR(rtPCR)

The random shotgun method is used in

genome sequencing.

amplification of unknown DNA.

forensic microbiology.

transforming plant cells with recombinant DNA.

RFLP analysis.

genome sequencing

Which of the following methods could be used to identify the source of an outbreak?

reverse genetics

artificial selection

DNA fingerprinting

production of a recombinant protein

DNA fingerprinting 

DNA fingerprinting can be used to identify microorganisms recovered from an outbreak and demonstrate whether they came from the same or different sources

Bioinformatics is the use of computer technology to compare and analyze genome sequence.

True

False

True

The Bt toxin derived from Bacillus thuringiensis has been introduced into some crop plants to make them resistant to insect destruction.

True

False

True

The application of "suicide" genes in genetically modified organisms ________.

deletes genes necessary for modified organism's growth

prevents the growth of the modified organisms in the environment

provides for resistance of the modified organisms to pesticides

kills the modified organisms before they are released in the environment

provides a means to eliminate non-modified organisms

prevents the growth of the modified organisms in the environment

Which of the following applications of recombinant DNA technology is NOT controversial?

genetic screening

biological weapons development

genetic food modification

metagenomics

metagenomics

This is the study of DNA taken directly from environmental or clinical samples and is not a controversial application of recombinant gene technology.

What is innate immunity?

It involves T cells and B cells.

It provides increased susceptibility to disease.

It involves a memory component.

It is nonspecific and present at birth.

It is slower than adaptive immunity in responding to pathogens.

it is nonspecific and present at birth

TLRs attach to all of the following EXCEPT

flagellin.

AMPs.

peptidoglycan.

PAMPs.

LPS.

AMP’s

Innate immunity includes all of the following EXCEPT

activation of complement.

production of antibody.

inflammation.

phagocytosis.

production of interferon.

production of antibody

Which of the following statements about innate immunity is true?

Innate immunity involves specific recognition of microorganisms via a memory response.

It involves the activity of B and T cells.

The innate immune response does not have a mechanism for detecting invading microorganisms. It is activated only in response to tissue damage or a signal from an infected cell.

Innate immunity is present at birth.

Innate immunity is present at birth

All of the following protect the skin and mucous membranes from infection EXCEPT

multiple layers of cells.

the "ciliary escalator."

saliva.

tears.

HCl.

HCI

The main function of the "ciliary escalator" is to:

Remove microorganisms from the lower respiratory tract

Propel inhaled dust and microorganisms away from the mouth, toward the lower respiratory tract

Trap microorganisms in mucus in the upper respiratory tract

Remove microorganisms from the gastrointestinal tract

Trap inhaled dust and microorganisms in mucus and propel it away from the lower respiratory tract

Trap inhaled dust and microorganisms in mucus and propel it away from the lower respiratory tract

Which non-specific defense mechanism is mismatched with its associated body structure or body fluid?

mucociliary escalator – intestines

lysozyme – tears and saliva

cerumen and sebum – ear

keratin and tightly packed cells – skin

very acidic pH – stomach

mucociliary escalator – intestines

Unbroken skin poses a substantial barrier to microbes. All of the following contribute to this barrier except _____________.

complement proteins found in perspiration

fatty acids within sebum

dryness of the skin

the tightly packed layer of dead, keratinized cells

complement proteins found in perspiration

Microorganisms that are members of the normal microbiota are also known to cause disease.

True

False

true

Normal microbiota provide protection from infection in each of the following ways EXCEPT

they make the chemical environment unsuitable for nonresident bacteria.

they compete with pathogens for nutrients.

they change the pH of the environment.

they produce antibacterial chemicals.

they produce lysozyme.

they produce lysozyme

Normal microbiota provide resistance to disease in all of the following ways except __________________.

microbial antagonism

promoting the development and maturation of the immune system

serving as prebiotics

competitive exclusion

serving as prebiotics

Which of the following exhibits the highest phagocytic activity?

basophils

neutrophils

eosinophils

macrophages

erythrocytes

macrophages

A differential cell count is used to determine each of the following except:

Leukopenia

The numbers of each type of white blood cell

Leukocytosis

The number of red blood cells

The total number of white blood cells

the number of red blood cells

Which of the following statements about fixed macrophages is not true?

They are cells of the mononuclear phagocytic system.

They are mature monocytes.

They develop from neutrophils.

They are found in certain tissues and organs.

They gather at sites of infection.

they develop from neutrophils

Which of the following is involved in resistance to parasitic helminths?

basophils

monocytes

lymphocytes

neutrophils

eosinophils

eosinophils

Macrophages arise from which of the following?

eosinophils

lymphocytes

basophils

neutrophils

monocytes

monocytes

If one is examining a blood smear from a patient with a parasitic worm infection, which of the following leukocytes would be found in increased numbers?

Lymphocytes

Eosinophils

Monocytes

Basophils

eosinophils

The maturation of stem cells to become red blood cells occurs in the red bone marrow.

True

False

true

Which of the following is an effect of opsonization?

increased adherence of phagocytes to microorganisms

cytolysis

inflammation

increased diapedesis of phagocytes

increased margination of phagocytes

increased adherence of phagocytes to microorganisms

Phagocytes utilize all of the following to optimize their interaction with pathogens except:

Lysozyme

Opsonization

Complement system

Chemotaxis

Trapping a bacterium against a rough surface

lysozyme

Neutrophils with defective lysosomes are unable to

migrate.

attach to microorganisms and other foreign material.

undergo chemotaxis.

engulf microorganisms and other foreign material.

produce toxic oxygen products.

produce toxic oxygen products

Lysozyme and penicillin have similar mechanisms of action in that they both cause damage to the bacterial ________.

cell wall

capsule

ribosomes

cell membrane

DNA

cell wall

Death results if body temperature rises above

39° to 41° C.

44° to 46° C.

30° to 32° C.

35° to 37° C.

44° to 46° C

Which of the following statements concerning phagocytosis is true?

Adherence always requires opsonization.

Phagocytes cannot ingest microorganisms unless they are coated with antibodies.

Bacteria are digested when the phagosome fuses with a lysosome.

Phagocytes ingest microorganisms by using protein transporters that are specific to the bacteria.

Bacteria are digested when the phagosome fuses with a lysosome

Digestion of microorganisms occurs in phagosomes.

True

False

false

All of the following increase blood vessel permeability EXCEPT

lysozymes.

leukotrienes.

prostaglandins.

kinins.

histamine.

lysozymes

A child falls and suffers a deep cut on her leg. The cut went through her skin, and she is bleeding. Which of the following defense mechanisms will participate in eliminating contaminating microbes?

Acidic skin secretions

Phagocytosis in the inflammatory response

Mucociliary escalator

Lysozyme

Normal skin flora

Phagocytosis in the inflammatory response

Margination refers to which of the following?

The movement of phagocytes through walls of blood vessels

The adherence of phagocytes to microorganisms

The chemotactic response of phagocytes

Adherence of phagocytes to the lining of blood vessels

Dilation of blood vessels

Adherence of phagocytes to the lining of blood vessels

The swelling associated with inflammation decreases when the fluid

returns to the blood.

goes into lymph capillaries.

is transported into macrophages.

is excreted in urine.

is lost as perspiration.

goes into lymph capillaries

All of the following are effects of histamine EXCEPT

swelling.

vasodilation.

redness.

fever.

pain.

fever

All of the following are effects of kinins EXCEPT

increased blood vessel permeability.

production of antibodies.

vasodilation.

drawing in neutrophils to infected or injure area.

chemotaxis of phagocytic granulocytes.

production of antibodies

Which of the following is mismatched?

chemotaxis – chemical degradation inside a phagolysosome

scab – dried blood clot over injured tissue

diapedesis – movement of leukocytes between capillary walls cells out of blood and into tissue

pus – tissue debris and dead phagocytes in a white or yellow fluid

abscess – a cavity created by tissue damage and filled with pus

chemotaxis – chemical degradation inside a phagolysosome