Unit 4 Review Questions
The enzyme DNA _______ synthesizes the RNA primers required by DNA polymerases during replication
primase
A single DNA molecule made from two different sources is called _________ DNA.
recombinant
Each aminoacyl-tRNA synthetase present in a cell recognizes _____ of the 20 common amino acids. (indicate the number)
1
Place the following steps in the reproductive cycle of a temperate bacteriophage in order, with the step following attachment at the top and the step preceding release at the bottom. Assume that the lysogenic cycle is initiated first.
1. injection (penetration) 2. integration 3. propagation 4. induction 5. synthesis 6. assembly
How many nucleotide bases are in one codon?
3
Which of the following is characteristic of the lytic cycle?
A large number of phages is released at a time.
What are the two features used by the CDC to diagnose AIDS?
At least one of the HIV-associated diseases or syndromes T-cell count in the blood below 200/ml
For proteins that are targeted to the ER, where is the signal sequence usually located?
At the beginning of the protein (first several amino acids added during translation)
Bacteria-infecting viruses are also known as which of the following?
Bacteriophage
Which of the following statements are TRUE regarding archaeal viruses and bacteriophages?
Both can have double-stranded DNA as their genome. Archaeal viruses are more diverse in their morphologies than bacteriophages.
Select the functions of the ribosome.
Forming peptide bonds Decoding the transcribed message
The universality of the genetic code is evidence for which of the following?
Common evolutionary heritage
Which of the following is a receptor for HIV virions?
CD4 antigen
HIV attaches to the cells by interacting with which of the following?
CD4 receptor on their surface
What type of cells are targeted and ultimately destroyed by HIV?
CD4+ cells
Which of the following best defines nutritional mutants?
Cells that can only grow if the medium is supplemented with certain nutrients
Next generation sequencing technologies use variations of ___--- to produce the DNA that will be sequenced
PCR
Virtually all viruses that have been implicated in human cancer use _______ as their nucleic acid at some point during their replicative cycle.
DNA
Viruses placed in Group I and II of the Baltimore classification have single or double-stranded _____ as their genetic material
DNA
The enzyme that relieves DNA supercoiling ahead of the replication fork is
DNA gyrase
Addition of ubiquitin marks proteins for which of the following?
Degradation
In the ribosome, no additional input of energy is needed when peptide bonds are formed. Why? Multiple choice question.
During the charging reaction, an ATP is used to attach the amino acid to the tRNA, producing an activated intermediate.
Coactivators can affect the structure of chromatin by acting as which of the following?
HIstone acetylases
The experiments with radioactively labeled phage that showed that DNA was the genetic material were performed by
Hershey and Chase
What are the two most common routes of HIV transmission?
Intimate sexual contact Sharing of needles among intravenous drug users
Of the following list, which are the two most important types of cells killed by HIV?
Macrophages and T-helper cells
The experiments used to distinguish between the three potential DNA replication mechanisms were performed by
Meselson and Stahl.
_______ involves isolating DNA from an environmental sample, sequencing it, and comparing it to known sequences in DNA databases.
Metagenomics
Viruses in Group III of the Baltimore classification have double-stranded RNA. How do they express their genomes?
One of the RNA strands is copied into an mRNA which is then translated.
Beadle and Tatum concluded that a single gene controlled the synthesis of a single enzyme. This is referred to as which of the following?
The one-gene/one-enzyme hypothesis
If a scientist introduces a deletion of three nucleotides in a gene, what is the expected effect of that deletion on the amino acid sequence following it?
The sequence of amino acids following the deletion will be normal.
Which of the following are true of influenza viruses?
Their genome is composed of segmented RNA. Protein spikes on the capsid surface are made up of hemagglutinin and neuraminidase.
Golden rice is genetically modified to produce β-carotene which alleviates which deficiency?
Vitamin A
Based on replication proteins, DNA replication in archaea is most similar to that of
eukaryotes
A human gene can be placed into the genome of a bacterium, such as E. coli, and the bacterium will make the encoded protein. How is that possible?
This is possible because of the universal genetic code
What term refers to the fact that a virus may target only a specific set of cells once inside a multicellular host?
Tissue tropism
Why do eukaryotic cells have multiple origins of replication?
To ensure timely replication of multiple, relatively large chromosomes
What is the purpose of transformation?
To introduce new DNA into a cell Reason: In transformation, a cell uptakes a foreign piece of DNA.
miRNAs were discovered during studies of the lin-4 gene in C. elegans; this gene encodes for which of the following?
Two small RNAs (22 and 61 nucleotides, respectively)
Which of the following sets of nucleotides is a valid mRNA codon?
UUC
HSV-1 and HSV-2 can be reactivated when the host is exposed to ______ light
UV/ultraviolet
How does the replication of HIV proceed after it enters a host cell?
Viral RNA is reverse-transcribed, incorporated into the host cell's DNA, and eventually used to produce many copies of the virus
Which infectious agents are composed solely of RNA?
Viroids
Choose the features that are common to viruses involved in human cancer.
Virtually all of them use DNA as their genetic material at some point in their replicative cycle. They all possess a mechanism that ensures their genome is stably inherited during cell division. They all establish long persistent infections in the human body.
Which of the following statements most accurately describes the host specificity of viruses?
Viruses infect all types of organisms, but individual viruses are very limited in the species and cell types they can infect.
Which of the following statements accurately describes glucose repression in bacteria.
When both glucose and lactose are present, the lac operon is not induced and bacteria will only use the glucose.
Lambda phage and most temperate phages can enter the lytic cycle by derepressing their prophage at which of the following times?
When the host cell is stressed
What is the order of the lac genes following the operator?
Z, Y, A
A TALEN is
a TALE protein fused to an nuclease.
Which organism has the simplest transcription regulation?
a bacterium, such as E. coli
In RNA interference,
a gene is silenced by using a small double stranded RNA, which allows scientists to determine the gene's function
Viruses are unable to reproduce without which of the following?
a host cell
The TALE repeat domain of a TALE protein contains
a middle pair of highly variable amino acids surrounded by conserved amino acids.
_______ are fuels produced by harvesting and using biotechnology to process the biomass of plants or algae.
biofuels
all viral particles (virions) lack
cytoplasms and are not cells, as they generally lack metabolic activity and cannot replicate outside of a host.
A ____ is the loss of a portion of a chromosome.
deletion
This model of DNA replication suggests that newly synthesized strands of DNA have mixtures of parental and newly synthesized strands of DNA:
dispersive
An ______ cuts DNA internally and an ______ cuts at the ends of DNA.
endonuclease; exonuclease
E. coli polymerases I, II, and III have 3' to 5' ______ activity, which provides them with a proofreading function, i.e. they can remove a mispaired base.
exonuclease
Tobacco mosaic viruses (TMV) have what type of capsid?
helical capsid
Match these enzymes involved in DNA replication with their function.
helicase - unwinds the double helix gyrase - relieves coiling in DNA strands ahead of the replication fork primase - makes a 10-12 bp complementary primer to the DNA polymerase - attaches a nucleotide to the 3' end of the DNA strand
DNA replication in eukaryotic cells is complicated by the fact that eukaryotic cells have
linear chromosomes
During RNA interference genes are usually
knocked down
In an aging cell, the activity of telomerase would be
low
Ribosomes move relative to which of the following RNAs?
tRNA and mRNA
Current next-generation sequencing technologies use
variations of PCR to obtain DNA that will be sequenced.
A phage is a type of _____ that infects _____ cells.
virus bacteria
Before it can bind to the promoter, a eukaryotic RNA polymerase II has to be recruited by
several transcription factors
Sudden major changes to the HA and NA genes of influenza viruses due to reassortment are known as antigenic ____
shift
Due to the degenerate nature of the genetic code, some base substitutions are ______, that is, the mutated DNA codon encodes the same amino acid in the protein. Listen to the complete question
silent
A base substitution mutation that results in the production of an unaltered protein is known as a
silent mutation
The genome of HIV consists of two identical ________- stranded, ______-sense RNA molecules.
single plus, positive, or +
Bacterial replication (for example in E. coli) begins at
single origin
When the double stranded DNA helix is unwound, two single strands of DNA are formed. These strands have to be stabilized because their hydrophobic bases are exposed to water. The proteins that stabilize the two single strands are called
single-strand binding proteins
Typically, gel electrophoresis is used to separate DNA fragments created through restriction based on which of the following?
size
Choose the three types of persistent human viral infections based on the amount of virus present and when it is produced.
slow chronic latent
______ DNA fragments move faster through a gel polymer than _____ fragments and will be located closer to the bottom of the gel
smaller larger
The acceptor _____ and the_____ loop are the two functional ends of tRNA.
stem anticodon
The DNA backbone is composed of (choose all that apply)
sugars. phosphate groups.
The third step of a PCR cycle where Taq polymerase uses dNTPs to synthesize complementary DNA strands is referred to as which of the following?
synthesis
Short, repeated sequences of DNA are characteristic of
telomeres
Which of the following are short repeats of DNA on the ends of eukaryotic chromosomes?
telomeres
Griffith's experiments were important because they showed
that the genetic material could be passed from one cell to another
The Cre-Lox system was isolated from the bacterial virus P1. In this system
the Cre enzyme will remove any sequence of DNA flanked by the Lox sequence.
In RT-qPCR,
the amount of DNA produced during the PCR step is measured in real time.
Phage conversion is
the change in the phenotype of a lysogenic bacterium caused by the prophage.
Transmissible spongiform encephalopathies (TSEs) cause
the development of numerous small cavities in the brain as neurons die.
Some studies suggest that there is more genetic variation in the viruses of an HIV-infected patient than in all influenza viruses worldwide. This, and difficulties in vaccine development may be attributed to
the inability of reverse transcriptase to proofread, which results in a high mutation rate.
The problems in replicating the ends of linear chromosomes are caused by
the need for a primer the directionality of polymerases
In type I diabetes
the pancreas cannot produce insulin, which results in a rise in blood sugar
Scientists can use hybridization to detect a specific sequence using a fluorescently or radioactively labeled probe. In the case of FISH
the probe is fluorescently labeled and the target is DNA in cells with intact chromosomes.
In transcription, which DNA strand has a sequence that is identical to the produced RNA (except that U in RNA is T in DNA)?
the sense strand
In a virion, the term nucleocapsid refers to
the viral genome and a tightly associated protein shell.
DNA repair mechanisms have likely evolved because
there is no way for cells to avoid exposure to mutagens
Once inside a host, many viruses will only target a specific set of cells. This is known as
tissue tropism
The purpose of PCR is
to produce millions of copies of a particular DNA sequence.
In both prokaryotes and eukaryotes, gene regulation most commonly occurs at the level of _____ initiation.
transcription
RNA polymerase II, together with all of the general and specific transcription factors and associated mediators and co-activators, form the eukaryotic ________ complex.
transcription
In addition to a DNA-binding motif, regulatory proteins have a domain that allows interaction with which of the following?
transcription apparatus
The region containing the RNA polymerase, the DNA template, and the growing RNA transcript is called the
transcription bubble
In all cells, gene regulation most commonly happens at which level?
transcription initiation
During ___, a bacterial cell is allowed to uptake foreign DNA
transformation
a ____ organism is one that has genes introduced into it via genetic engineering.
transgenic, genetically modified, or GM
There are two broad categories of base substitutions based on whether the new base is similar to the old one. A change of ATA to ACA would be categorized as a _______, while a change of CCT to ACT would be categorized as a _____.
transition transversion
Base substitution mutations fall into two categories: in ________, a pyrimidine is substituted for another pyrimidine, or a purine is substituted for a purine; in ______, a pyrimidine is substituted for a purine, or vice versa.
transitions transversions
In some cases, the initiation of translation is regulated when_______ ________ proteins bind to the beginning of an mRNA so that the mRNA cannot attach to the ribosome.
translation repressor
______ is a change in a chromosome resulting from a fragment of chromosome breaking-off and attaching to a nonhomologous chromosome.
translocation
The disease that causes the development of numerous small cavities in the brain of infected individuals due to death of neurons producing a spongy appearance is called
transmissible spongiform encephalopathy.
The Ti plasmid of A. tumefaciens contains gene that cause the formation of a plant ______ or a gall, in infected tissues.
tumor
The genome of HIV consists of
two single-stranded, plus-sense RNA molecules.
____ is a condition characterized by viruses freely circulating in the blood or lymph.
viremia
When outside of a host cell, an individual viral particle is known as a(n)
virion
Identify the disease agent that ranges in size from about 20-250 nm in diameter.
virus
The enzyme reverse transcriptase was isolated from what type of organism?
virus
Franklin determined that the structure of DNA was helical based on
x-ray diffraction analysis
Which DNA polymerase removes and replaces RNA primer segments in the synthesis of the lagging stand because it has 5' to 3' exonuclease activity.
1
Place the following elements in the lac operon as they are organized on the chromosome. Start at the top with the gene/site that follows the gene for the repressor protein (lacI).
1. CAP site 2. Plac (promoter) 3. O (operator) 4. lacZ 5. lacY 6. lacA
One of the first miRNA that was discovered by scientists involves the lin-4 gene of C. elegans. The product of the lin-4 gene is which of the following?
A miRNA that inhibits the translation of the lin-14 gene because it is complementary to lin-14 mRNA
Alternative splicing allows which of the following? Multiple choice question.
A single transcript can be spliced into different mRNAs
Which of the following describes a virus?
A small biological particle comprised of nucleic acid enclosed in a protein coat
How do restriction enzymes work?
By binding to a specific base sequence and then cleaving the DNA backbone in two locations - one on each strand Reason: Restriction enzymes recognize specific sequences in DNA.
How can a TALE protein be engineered to recognize a specific sequence of DNA?
By combining several TALE repeat domains
How can proteins interact with DNA and recognize DNA sequences without unwinding the DNA double helix?
By interacting with the major groove of the double helix
How was the genetic code deciphered?
By using cell-free biochemical systems to produce proteins based on synthetic mRNAs
Which of the following are modifications that have been documented during RNA editing?
Chemical modification of bases that change their base-pairing properties Insertion of uracil residues
In a DNA library, DNA fragments are spliced together with a specialized DNA molecule that allows the storage and propagation of the library. What are those specialized DNA molecules called?
Cloning vectors
Of the following list, choose all that may be found in a viral particle.
DNA An envelope RNA A protein shell not: RNA, nucleus, or a rough ER
Viruses that contain _____ as their genetic material are often assigned to species group; the same is not true of viruses with ______ as their genetic material.
DNA RNA
Which enzymes did Avery, MacLeod, and McCarty use in order to identify the genetic material
DNA digesting enzymes protein digesting enzymes RNA digesting enzymes
Which of the following statements about mRNAs in prokaryotes and eukaryotes is true?
Eukaryotic mRNAs are typically much more stable than prokaryotic mRNAs.
Choose all factors that can trigger HSV-1 and HSV-2 reactivation in a human host.
Exposure to UV light Hormonal changes Immune suppression
A virus that has a structure resembling a soccer ball, with 20 equilateral triangular facets is which of the following?
Icosahedral virus
After the initial acute disease (painful blisters) subsides due to an immune response, where can HSV-1 and HSV-2 be found?
In the nuclei of sensory neurons that innervate the site of infection
Which of the following statements about proteins in cells is true?
Old unused proteins in the cell are removed by specialized structures in a controlled way.
Most deaths attributed to AIDS are caused by which of the following?
Opportunistic infections that would typically not harm a host with a normal immune system
What is the name of the subunit that acts as the sliding clamp, which keeps the replicating enzyme complex attached to the template in eukaryotic cells. Multiple choice question.
PCNA
The RNA interference pathway in this type of organism is much more complex than that of animals.
Plants
____ mutations, also known as single _____ variations change only a single base in the sequence of DNA.
Point nucleotide
What do the first two stages of wastewater treatment involve?
Primary: physical and chemical removal of particulates; Secondary: microbial digestion
Which of the following enzymes involved in DNA replication are found at the replication fork in all three types of cells (bacterial, archaeal, and eukaryotic)?
Primase Polymerases Clamp loader Sliding clamp Helicase
The second step of a PCR cycle involves which of the following?
Primer annealing
Which of the following statements most accurately describes the function of the proteasome?
Proteins marked with ubiquitin enter one end of the proteasome and exit the other end as amino acids or peptide fragments.
Which of the following is a difference between regulatory proteins with leucine zipper and helix-turn-helix DNA binding motifs?
Proteins with leucine zippers have two different recognition helices, while proteins with helix-turn-helix motifs are made of two identical units.
Viroids are infectious disease agents in plants that are composed solely of circular _____
RNA
Which of the following are forms of post-transcriptional regulation in eukaryotes?
RNA editing RNA interference Alternative splicing mRNA degradation rate
Viral genomes may be composed of ______ or ______ and may be _______-stranded or ______-stranded.
RNA or DNA single double
Match the eukaryotic RNA polymerase with its function.
RNA polymerase 1 - transcribe rRNA RNA polymerase 2 - transcribes mRNA RNA polymerase 3 - transcribes tRNA
Select the components of the eukaryotic initiation complex.
RNA polymerase II Promoter Transcription factors
In the following list, choose all that are components of the eukaryotic transcription complex.
RNA polymerase II Specific transcription factors Mediators and co-activators General transcription factors
Why do RNA viruses appear to have higher rates of mutation?
RNA replication is error-prone.
Reverse transcriptase catalyzes which of the following reactions?
RNA to DNA
Most multicellular organisms execute complex developmental programs that ensure the production of functioning organisms; these developmental programs are heavily dependent on coordinated changes in ____ _____
gene expression
How do eukaryotic transcription factors help form the initiation complex?
They recruit RNA polymerase to the promoter
Which process can produce multiple transcripts from the same gene in eukaryotes?
alternative splicing
In the ribosome, a peptide bond is formed between the __ end of the amino acid at the A site and the ____ end of the amino acid attached to the tRNA at the P site.
amino carboxyl
The enzymes that catalyze the attachment of _______ _______to tRNA molecules are known as aminoacyl-tRNA synthetases.
amino acids
A charged tRNA is composed of the tRNA to which the following has been attached:
an amino acid
In immunoassays, a molecule is detected by using a specific ______ against it.
antibody
Protease inhibitors prevent the cleavage of HIV's proteins into the smaller proteins that are necessary for viral
assembly and maturation.
The poly-A tail of most mature eukaryotic mRNAs is found
at the 3' end of the transcript
Match each stage in bacteriophage reproductive cycles to the letter representing that stage.
attachment penetration synthesis assembly release integration propagation induction
A ___ ______mutation occurs when one base pair in DNA is replaced with a different one, for example, AAATCG mutates to AATTCG.
base substitution
What is the substitution of one base pair for another in DNA called?
base substitution mutation
During _____, microorganisms are used to degrade hydrocarbon pollutants in the environment.
bioremediation
The use of microorganisms to degrade or metabolize (incorporate into microbial biomass) hydrocarbon pollutants is called ________
bioremediation
The benefits of eating golden rice include a significant reduction in the number of cases of which of the following?
blindness
Telomeres are related to
cellular aging
Human papilloma viruses are known to cause several types of cancer in the human body, but the most significant one is ______ cancer.
cervical
______ ______ allows the creation of knockout animals, in which a gene is knocked out only in cells of a specific tissue or at a specific time during development.
conditional inactivation
Which best describes the purpose of gene therapy?
defective genes are restored or replaced.
Eukaryotic promoters are binding sites for _____ transcription factors
general
A(n) ------- disease is a disease that appears in the population for the first time, or that spreads to a new geographical area.
emerging
Prokaryotic gene regulation is geared toward responding to changes in the _______; in multicellular eukaryotes, gene regulation is critical for directing ______ and maintaining ______.
environment, development, homeostasis
The use of biological process to protect and repair the environment from negative human impacts is part of a growing area of biological applications called
environmental biotechnology
DNA _____ is a technology that can identify and distinguish among individuals based on variations in the number of short tandem repeats in their DNA.
fingerprinting
A sequence of DNA flanked by Lox sites is said to be
floxed
Scientists introduce mutations in genes in order to understand their
function
HIV enters a host T-helper cell by first binding to the CD4 receptor and a coreceptor such as CCR5, and then _______ with the cell membrane.
fuses
The Ti plasmid of A tumefaciens can be used to transform plant cells and create transgenic plants by replacing the genes responsible for _______ formation and replacing them with a gene of interest.
gall or tumor
Transcription factors that are necessary for the assembly of a transcription apparatus and recruitment of RNA polymerase II to a promoter are called which of the following?
general transcription factors
Because the ____ ____ is nearly universal, a gene from one organism can be placed into a completely different organism and direct the production of the same protein.
genetic code
Attachment of HIV occurs when the _______ glycoprotein binds to the _______ receptor on the surface of an immune system macrophage or T cell.
gp120 CD4
When they enter the cell, viruses in Group II of the Baltimore classification
have to convert their single-stranded DNA into double-stranded DNA.
A viral capsid with an overall _______ structure has a rodlike or threadlike appearance.
helical
Most viruses have a capsid that is _______ or ______ in terms of its basic structure and symmetry.
helical icosahedral
The enzyme ____ uses ATP to unwind the DNA template.
helicase
After the immune system can no longer control HIV, it starts killing cells expressing the CD4 antigen. Of those cells, the most important types are the T-_____ cells which coordinate the immune response and the _______ which engulf pathogenic bacteria.
helper macrophages
In fission yeast, plants and Drosophila, small RNAs and the RNA silencing pathways have been implicated in the formation of
heterochromatin
A virus' ____ ____ refers to the suitable cells they can infect
host range
The number of species and cell types that a virus can infect refers to a virus'
host range
Regarding Meselson and Stahl's experiment, the primary difference between the proposed models of DNA replication was related to
how the parental strands were incorporated into the daughter strands
What is the term(s) used for a probe attached to a complementary piece of DNA?
hybridization
The basic capsid shape of most animal viruses is a(n)
icosahedron
The damage to tissues during an infection with the influenza virus is usually due to the ______ response of the host
inflammatory
The association of transcription factors and RNA polymerase II at the eukaryotic promoter is called the ______ complex.
initiation
What types of drugs aim to suppress the proliferation of HIV in the body by preventing the viral genome from being incorporated with the host cell's DNA?
integrase inhibitors
In order for HIV to replicate in a white blood cell, it must ________ its double-stranded DNA into a random host chromosome.
integrate
Eukaryotic genes may contain non-coding regions known as ____ because they interrupt the sequence of a gene.
introns
The noncoding DNA sequences in a gene are termed which of the following?
introns
To create a functional RNA, the pre-mRNA undergoes a process known as splicing. During the splicing process, the ______ are removed and the remaining _______ are connected to each other.
introns -cut out exons - remain
Scientists can use a number of techniques to inactivate one or more genes in an animal, such as mouse. Such animals are called
knockout animals
On this strand, the removal of the last primer leaves a gap that cannot be primed at the ends of the chromosome.
lagging
The two subunits that make up any ribosome are called the _____ subunit and the ____ subunit.
large small
During DNA replication, the_________ strand is synthesized continuously while the _________ strand is synthesized as small fragments that are connected to each other to form a continuous strand.
leading lagging
The enzymes in the replisome are active on
leading and lagging strands
Compared to archaeal viruses, bacteriophages are
less diverse in their morphologies.
A collection of many different recombinant molecules that can be maintained and replicated (when needed) is called a DNA
library
As the lagging strand is being synthesized, adjacent Okazaki fragments are joined by the enzyme DNA ________
ligase
A host bacterial cell which has had phage DNA integrated into its genome is known as a(n)
lysogen
The DNA segment that is integrated into a bacterial host cell's genome is called a prophage, and the resulting cell is called which of the following?
lysogen
A viral reproductive cycle that includes the production of a prophage is the _______ cycle
lysogenic
Bacteriophage contribute DNA to their hosts during the ________cycle, which may allow phage genes to be expressed with those of the host.
lysogenic
The reverse transcriptase enzyme of HIV is less accurate than other polymerases, which causes it to make errors relatively frequently. As a result, HIV has a high ______ rate.
mutation
When tightly associated, the genome and the surrounding protein shell of a virus are collectively known as the
nucleocapsid
Viruses are
obligate intracellular parasites
During semiconservative DNA replication
one of the strands in each new double helix comes from the original molecule, and one is newly synthesized.
Repressors are proteins that bind to regulatory sites on DNA called _______. These prevent transcription.
operators
A(n) ____ is a cluster of genes that are part of a single transcription unit that is under the control of a single promoter.
operon
Infectious proteins that can cause transmissible spongiform encephalopathies are called
prions
What disease agents are infectious proteins that can cause transmissible spongiform encephalopathies?
prions
Which of the following infectious disease agents are composed solely of protein?
prions
Molecular cloning is a term often used to refer to the process of
producing recombinant DNA
Transcription and translation of an mRNA molecule occur simultaneously in
prokaryotes
In ______, the typical half-life of an mRNA transcript is 3 minutes, in contrast, mRNAs in ______ are usually very stable.
prokaryotes; eukaryotes
In a bacterial transcription unit, the role of the _____ is to form a recognition and binding site for the RNA polymerase.
promoter
A phage DNA segment that is integrated into a host bacterial cell's genome during the lysogenic cycle is known as a(n)
prophage
Proteins marked with ubiquitin enter the _______ at one end and exit the other side as amino acids or polypeptide fragments.
proteasome
Repressors are which type of molecules?
protein
Virions lack the enzymes necessary for the synthesis of _____ , as well as most of the enzymes necessary for the replication of _____ acids
protiens nucleic
TALE proteins contain several sets of a repeating 34 amino acid sequence known as the TALE ____ ____
repeat domain
The DNA controlled by an origin is called a
replicon
Glucose ____ occurs when bacterial cells are grown in the presence of glucose and lactose. In the presence of both sugars, bacteria will preferentially use the glucose before using the lactose.
repression
A _____ _______ is an enzyme capable of cutting DNA at specific sequences.
restriction endonuclease
Which of the following is an enzyme that cuts DNA at a specific sequence?
restriction enzyme
HIV particles that infect human host cells carry a viral enzyme called ______ ______ which is needed by the virus to make DNA from RNA.
reverse transcriptase
Once it enters the cytoplasm of a host cell and sheds its capsid, replication of HIV begins when ________ _________ is used to synthesize a double strand of DNA from the viral RNA.
reverse transcriptase
A scientist used reverse transcriptase to make cDNA from isolate cellular mRNA. After the cDNA is produced, it is used as a template in a PCR reaction. This is known as Multiple choice question.
reverse transcription PCR
A helical capsid has a shape that resembles which of the following?
rod or thread
Rank the following cells and particles in order according to size, with the smallest at the top and largest at the bottom.
1. protein 2. T2 bacteriophage 3. Influenza virus 4. E. coli bacterium 5. Eukaryotic cell
In the Baltimore classification of viruses, there are ______ groups of viruses and every known virus can be placed in only one such group based on the way it ______ its genome.
7 forgot lol
During elongation in the ribosome, the amino end of the amino acid at the _____ site is connected to the carboxyl end of the amino acid attached to the tRNA at the_____ site.
A P
A class of chromatin-remodeling complexes that function as molecular motors that modify DNA and histones are dependent on what molecule?
ATP
Charged tRNAs are brought to the A site in the ribosome by an elongation factor called .
EF-Tu
True or false: Eukaryotic transcripts are not modified after transcription.
False Eukaryotic transcripts can be modified with a 5' cap or 3' poly-A tail
True or false: Typically, once a protein is synthesized in a healthy cell, it will perform its function indefinitely because the cell environment is highly controlled.
False Reason: proteins lose their function with time and have to be removed in a controlled way.
Choose all the conventional systematic groups that are also used to classify viruses.
Family Order Genus
What is the effect of the initial acute disease episode after infection with an HSV-1 or HSV-2?
Formation of painful blisters at the site of infection
Some corepressors that alter chromatin structure have been shown to act as which of the following?
Histone deacetylases
How do viruses replicate?
Host cells' transcription and translation systems are used to replicate the genome and create capsid proteins.
Why are humans resistant to glyphosate?
Humans do not make aromatic amino acids.
Which of the following statements is true regarding influenza vaccine development?
New vaccines are produced each year to keep up with the virus, which exhibits high rates of mutation.
This type of mutation happens when a single base in DNA is substituted with another base, for example, an A becomes a G.
Point
Choose all characteristics of the transforming substance isolated by Avery, MacLeod and McCarty.
RNA-digesting enzymes did not affect its transforming ability. The elemental composition of the substance was very similar to that of DNA. Protein-digesting enzymes did not affect its transforming ability. DNA-digesting enzymes destroyed its transforming ability
How can a TALEN be used to edit the genome of a cell?
The TALE domains recognize a particular DNA sequence and the nuclease cuts it. When the cell repairs the cut, a mutation can be introduced.
Which feature of influenza viruses is the reason why vaccines against them have to be produced each year?
The viruses exhibit high levels of mutation.
What is the function of a promoter in eukaryotic cells?
They are binding sites for general transcription factors which recruit RNA polymerase in order to initiate transcription.
Of the following, which are characteristics of RNA viruses?
They can contain a single stranded or a double-stranded RNA genome. They require a viral encoded polymerase.
Which of the following is a shared property of all DNA-binding motifs?
They can interact with the major groove of DNA.
How do mediators and co-activators act?
They first bind a transcription factor and then bind another part of the transcription apparatus.
When is a lysogenic phage, such as lambda, likely to exit the lysogenic state and enter a lytic cycle?
When the host cell is stressed
The polymerase ______ _______ is used to quickly produce millions of copies of a particular DNA sequence.
chain reaction
Gene _____, also known as DNA ________, Correct Unavailable consist of a solid surface, which has been spotted with hundreds to thousands of different DNA sequences.
chips microarrays
______ mutations are changes that alter the structure of the chromosome itself.
chromosomal
The process of producing a recombinant DNA molecule is often called molecular
cloning
List several differences in prokaryotic and eukaryotic replication.
complexity of enzymology structure of chromosome (linear vs. circular) number of origins of replication
A scientist wants to create a knockout mouse, in which a gene is knocked out only in brain cells. One approach that can be used by the scientist is ______ inactivation
conditional
Archibald Garrod concluded that patients suffering from alkaptonuria lack the ____ necessary to catalyze the breakdown of homogentisic acid.
enzyme
Beadle and Tatum proposed the one-gene/one-_____ hypothesis. Today this relationship is referred to as the one-gene/one-_______ hypothesis.
enzyme polypeptide
Chromatin undergoes an _____ alteration when the alteration persists in the absence of a stimulus and is passed to daughter cells during cell division.
epigenetic
The two main types of liquid biofuels currently produced are
ethanol and biodiesel
E. coli polymerases I, II, and III have 3' to 5' __________ activity, which provides them with a proofreading function, i.e. they can remove a mispaired base.
exonuclease
Restriction sites are sequences recognized by restriction enzymes. They are often palindromic meaning that the sequence is
identical when read in the opposite direction on the complementary strand.
What are the two main ways in which a virus can spread to infect secondary sites in the human body?
in blood or lymph via neurological tissue
The TALE proteins and the CRISPR/Cas9 system are examples of molecular techniques used to perform
in vivo DNA editing
In E. coli, the lac operon is (induced/repressed) in the presence of lactose, and the trp operon is (induced/repressed) in the presence of tryptophan.
induced repressed
In E. coli, the lac operon is (induced/repressed) in the presence of lactose, and the trp operon is (induced/repressed) in the presence of tryptophan. Multiple choice question.
induced; repressed
Type I diabetes cannot be cured, but can be managed with daily ______ injections
insulin
Match the structural gene in the lac operon with the enzyme it produces.
lacZ - B-galactosidase lacY - permease lacA - transacetylase
Most AIDS-related deaths are not a direct result of HIV, but are caused by _________ infections that would not normally harm a host with a healthy immune system.
opportunistic
Genes from genetically modified corn frequently move to non-genetically modified corn plants because of outcrossing. This is a major concern to Multiple choice question.
organic farmers, whose fields are close to transgenic corn, because transgenic crops cannot be certified as organic.
The enzyme peptidyl transferase is required in the formation of _____ bonds by the ribosome.
peptide
The development of which technology led to the entire field of biotechnology?
recombinant DNA
New combinations of the hemagglutinin (H) and neuraminidase (N) protein spikes arise in the influenza virus when the viral genomes are _______ during infection of a single cell by more than one influenza virus.
recombined
A disease that was prominent in the past, and whose incidence suddenly increases after a period of low incidence, is called a _______ disease
remerging
Large complexes of proteins that include enzymes that can modify histones, DNA and chromatin structure itself are known as chromatin- ______ complexes
remodeling
_______ repair systems target a single kind of lesion in DNA and repair only that damage, while _______ repair systems use a single mechanism to repair multiple kinds of lesions in DNA.
specific nonspecific
types of repair mechanisms with how they work:
specific - Choice, target a single kind of lesion in DNA and repair that damage target a single kind of lesion in DNA and repair that damage nonspecific - Choice, repair multiple kinds of lesions in DNA, using a single mechanism repair multiple kinds of lesions in DNA, using a single mechanism
Which type of eukaryotic transcription factors can increase the level of transcription in certain cells in response to signals?
specific transcription factors
Identify the process the pre-mRNA undergoes to create a functional mRNA.
splicing
The process whereby different transcripts are made from a single gene is called alternative ______
splicing
In prokaryotes how do translation and transcription occur?
They are coupled.
Inspect the diagram of the arginine synthesis pathway in Neurospora crassa. If an arginine nutritional mutant can grow on minimal media, supplemented with ornithine, we can conclude which of the following?
mutant has a mutation in the argE gene
The two general categories of DNA repair are
nonspecific specific
where is telomerase found
only in eukaryotes
In the replisome, the ________ is composed of primase, helicase, and accessory proteins that prime the lagging strand.
primosome
The function of telomeres is to
protect the ends of chromosomes
In transcription, the DNA strand that is not copied is called the ____ strand
sense/coding
Place the types of mutations found in humans in the correct order going from most frequent (on top) to least frequent (at the bottom).
1. SNV mutations 2. Indels 3. Mobile element insertion 4. CNV mutation
Place the steps of lagging strand synthesis in the correct order (start at the top): Position 1 of 4 Synthesize primers using primase correct toggle button unavailable Synthesize primers using primase
1. Synthesizes primers using primase 2. synthesize DNA 3. Replace RNA primers with DNA 4. Seal nicks in the DNA
Place the steps of the HIV life cycle in order with the step following the introduction of the virus into the human bloodstream at the top.
1. The HIV gp120 glycoprotein attaches to the CD4 receptor of a CD4+ cell and one of two coreceptors 2. viral contents enter a CD4+ cell by endocytosis 3. Reverse transcriptase synthesizes a double strand of DNA that is complimentary to the viral RNA 4. Genetic material from the virus enter the nucleus and is incorporated into the host genome by a viral enzyme 5. Following a viable period of dormancy, the host cell machinery is directed to produce many copies of the virus 6. viral particles leave the host cell by budding
Place the steps in the process of creating transgenic plants in the correct order starting at top
1. The Ti plasmid is isolated from A. tumefaciens 2. The genes are responsible for gall formation are replaced with a gene of interest 3. The Ti plasmid is re-introduced into A. tumefaciens 4. A. tumefaciens is used to infect plant cells 5. Transformed plant cells are induced under the proper nutritional and hormonal conditions to produce a mature plant
Immunoassays can be used to detect viruses or bacteria. Place the steps in the process in the correct order, starting at the top. In this case, a virus is detected.
1. a solid surface is coated with antibodies against the virus of interest 2. an unknown sample is added 3. an antibody that has been linked to a fluorescent molecule is added 4. Fluorescence is detected
Place the steps of the lytic cycle of a T-series bacteriophage in order, assuming that the cycle begins with an inactive virion in the environment. The next step should be placed at the top of the list and the last step before a new generation of inactive virions is found in the environment should be placed at the bottom.
1. attachment (adsorption) of the virion to the outer surface of a bacterial cell 2. the bacteriophage tail contracts, allowing the tube to penetrate the bacterial cell wall 3. the genome of the bacteriophage is injected into the host cell cytoplasm 4. Viral components are synthesized using the cell's replication and translation machinery 5. assembly of new virions occurs 6. Virions are released when the cell host is lysed
Place the steps in the replication of the influenza virus in the correct order, starting at the top.
1. viral particles attach to host cell via the HA protein 2. virus is endocytosed 3. viral RNA segments are transported to the nucleus 4. viral genome is replicated and new viral proteins are made 5. viral capsids are assembled near the membrane 6. viral particles bud from the membrane acquiring an envelope in the process
How many hydrogen bonds are formed between adenine and thymine in the double DNA helix?
2
How many times does a restriction enzyme cut a double stranded piece of DNA at a given restriction site?
2
According to the CDC, in order for a person to have AIDS the level of T-cells in the blood must be below ______.
200/ml
X-ray diffraction was used to determine that the diameter of a DNA molecule is
2nm
Which of these is not a modification of eukaryotic transcripts?
3' cap
What percentage of the total mRNA produced as primary transcript exits the nucleus?
5%
Which of the following sequences is a palindrome?
5'-GAATTC-3'
A segment of DNA has the sequence 5'-ATGCCC-3'. The complementary sequence would be
5'-GGGCAT-3'
What is a "floxed" DNA sequence?
A DNA sequence flanked by Lox sites
When is the genome of HIV transcribed and translated to produce new RNA genomes, as well as proteins necessary for the assembly of new virions?
After the viral RNA has been copied into DNA and has integrated into a host chromosome
_____ is an inherited disease and the patients with this disease produce urine that contains homogentisic acid
Alkaptonuria
The production of different mature mRNAs from the same primary transcript is called which of the following?
Alternative splicing
The enzymes that catalyze the attachment of amino acids to tRNA molecules are known as which of the following?
Aminoacyl-tRNA synthetases
Bacillus thuringiensis is unique in that one of its gene products can act as which of the following?
An insecticide
During the acute phase of HIV infection, what is a typical load of viruses in the blood plasma? Multiple choice question.
As many as 5 x 106 virions per ml
Which of the following best describes how a phage undergoes the lytic cycle?
Attachment; penetration; synthesis; assembly; release
Which organism produces toxins that kill certain caterpillars and beetles?
Bacillus thuringiensis
Which of the following viruses uses the cellular machinery of a bacterium for its own replication?
Bacteriophage
The classification of viruses based on genome replication is known as the __________ classification after the scientist that first proposed it.
Baltimore
Why can't we treat HIV infections with a single drug?
Because if its high mutation rates, the virus quickly becomes resistant to any single drug.
Why is it difficult to classify influenza viruses based on their host?
Because there are four types of influenza viruses that can infect many different hosts (humans, birds, pigs, dogs, cats)
In their experiments, Avery, MacLeod, and McCarty isolated a substance, which had a transforming activity. Which of the following destroyed that substance's ability to transform bacterial cells?
DNA-digesting enzymes
Which of the following are symptoms associated with acute retroviral syndrome?
Diarrhea Joint pain Flu-like symptoms
Which of the following statements is true regarding vaccination for influenza?
Different vaccines are required to protect against the many different subtypes of the virus.
Which of the following is a mutation that changes the structure of the chromosome itself?
Duplication
Match the following proteins involved in cancer caused by HPV with their roles in the process.
E6 - A viral protein that binds and inactivates a cellular protein that can trigger apoptosis E7 - A viral protein that binds and inactivates pRb E2f- a cellular protein that is normally kept inactive by pRb p53 - a cellular protein that acts as a fail-safe to prevent aberrant cell division by triggering apoptosis
Which two genes of the HPV are necessary to drive tumorigenesis?
E7 E6
During the elongation stage of translation, the ribosome translocates relative to the mRNA and the tRNAs. This step requires the elongation factor _____ and the hydrolysis of _____
EF-G GTP
WHich of the following statements accurately describe vaccines against influenza viruses?
Each year the same vaccine is needed to boost the immune response.
The model organism used by Meselson and Stahl was
Escherichia coli.
Which have three different RNA polymerases?
Eukaryotes
In order for mismatch repair to occur in a bacterial cell, the enzyme machinery must be able to distinguish between the template strand and a newly synthesized strand. How is that achieved? Multiple choice question.
For a short period of time after replication, the sequence GATC is methylated at the A only on the template strand.
In order to bring a tRNA to the A site of the ribosome, the elongation factor EF-Tu must bind to a charged tRNA and
GTP
What term can refer to gene function at the level of traits or at the molecular level?
Gene expression
_____ therapy targets genetic diseases, while ____ ______ therapy is used to treat degenerative diseases, or tissue damage.
Gene' stem cell
In which of the following chromosomal entities are an individual's traits specified?
Genes Nucleotides by themselves cannot specify traits. Information that specifies traits is contained in the specific nucleotide sequences, called genes. Genes are located on chromosomes.
What herbicide kills actively growing plants by inhibiting the enzyme EPSP which is required to produce aromatic amino acids?
Glyphosate
Identify two benefits of glyphosate resistant plants.
Glyphosate breaks down readily in the environment. No weeding is necessary.
After an initial acute stage, the HIV is typically controlled by the immune system for years. Eventually, the immune response and viral loads increase. At this point,
HIV causes AIDS.fne
What are the two subtypes of HPV that are most commonly implicated in cervical cancer?
HPV 16 and HPV 18
The identification of specific DNA sequences in complex mixtures can be achieved using which of the following techniques?
Hybridization
How does HIV compromise the human immune system, allowing opportunistic infections to invade the body?
Infected CD4+ cells are killed until few are left.
What is the main reason for tissue damage during an infection with the influenza virus?
Inflammatory response of the host
The central dogma describes which of the following?
Information flow as DNA to RNA to protein
In the transcription elongation complex of eukaryotes, what is the function of the CTD?
It acts as a platform, which recruits elongation factors and RNA-modifying enzymes
How does HIV infect a CD4+ cell after binding to the CD4 receptor?
It binds to a coreceptor, and fuses with the cell membrane.
Select the statements that are true about ubiquitin.
It can be in the form of longer chains attached to other proteins. It can exist as an isolated molecule. It is made of 76 amino acids.
In the transcription elongation complex of eukaryotes, what is the CTD made of?
It consists of 7 amino acids repeated many times.
Choose all statements that accurately describe the transcription bubble.
It contains an RNA-DNA hybrid, about 9 nt long It moves along the DNA at a rate of about 50nt/sec The growing RNA strand protrudes from the bubble
Selects all features of the Ti plasmid.
It contains genes that normally cause the formation of a plant tumor It contains sequences that can transfer part of the plasmid into plant cells It is carried by the plant pathogen Agrobacterium tumefaciens.
What is the activity of Cre in the Cre-Lox system?
It is a recombinase
What is the consequence of the destruction of CD4+ cells by HIV to the human body?
It is no longer defended against invading bacteria and viruses, leading to opportunistic infections.
_____ mice can be used to determine the effect(s) of inactivated genes in the adult animal. This can tell scientists whether a gene is essential and what its function might be.
Knockout
During which of the following reproductive cycles does a bacteriophage integrate its own DNA into the host cell's genome?
Lysogenic cycle
Which of the following may take place during bacteriophage reproduction after the phage genome is injected into the host cell?
Lysogenic phage becomes lytic when cell stress causes depression of the prophage. New virus particles are synthesized by the cell and then released by lysis or budding. The viral DNA is integrated into the genome of the host cell, allowing it to replicate when the host cell divides.
The start codon of an mRNA specifies which of the following amino acids?
Methionine
The level of a particular mRNA in a cell can be determined using
RT-qPCR
The level of a particular mRNA in a cell can be determined using Multiple choice question.
RT-qPCR
Choose all applications of environmental biotechnology.
Reduce human impact on the environment Repair environmental damage Increase the sustainability of resources
Which of the following are considered parts of the lac operon?
Regulatory regions of the operon (promoter and operator) Genes required for utilization of lactose Repressor gene (lacI)
In translation termination, stop codons are recognized by what type of proteins?
Release factors
Which of the following approaches allows scientists to determine the function of a gene?
Replace a wild-type gene with a mutant copy Reason: Knowing the levels of expression of a gene does not tell scientists what the gene's product do in the cell. All cell types of an organism will have the same sequence of the gene.
What type of drugs are used to suppress HIV replication by inhibiting the enzyme used to synthesize DNA using viral RNA?
Reverse transcriptase inhibitors
Choose the different types of sequences that are typically spotted on a gene chip?
Short DNA sequences produced by PCR or RT-PCR Short DNA probes
What happens during antigenic drift in influenza viruses?
Small changes in the HA and NA genes accumulate due to mutation.
Which of the following statements accurately describes viruses?
Some viruses carry specific enzymes needed during the early stage of replication.
Which of the following are reasons why classifying viruses by disease they cause can be impractical?
Some viruses do not appear to cause any disease. The same disease can be caused by many different viruses. Some viruses can cause different disease in different context.
Name the complex that is composed of snRNPs and other proteins and is responsible for splicing of the introns:
Spliceosome
Which of the following describes how proteins are targeted for translation to the rough ER?
The initial amino acid sequence of these proteins serves as a signal sequence that targets them to the rough ER.
Which of the following is the most effective form of AIDS treatment, even though it does not completely eliminate the virus from the patient's body?
The use of a combination of drugs that target different stages of the HIV life cycle
HIV is usually controlled effectively by the immune system for the first several years following infection, but eventually causes AIDS when which of the following occurs?
The viral load increases. The immune response fails in its continued response to the virus.
Which of the following describes miRNAs and siRNAs?
They are small RNA molecules that are involved in posttranscriptional gene expression control.
What is the nature of terminators in bacteria?
They are specific sequences in DNA
Which of the following is a major difference between different DNA-binding motifs?
They employ different mechanisms to position and stabilize a recognition alpha helix in the major groove of DNA.
Viruses are unable to reproduce outside a host cell for which of the following reasons? Multiple choice question.
They lack ribosomes and the enzymes necessary for protein synthesis and nucleic acid replication.
Which of the following statements best describes viral genomes? Multiple choice question.
They may be circular or linear, single-stranded or double-stranded, and composed of DNA or RNA.
Select concerns that have been raised regarding genetically modified crops.
They may not be safe for human consumption. They may cause allergic reactions. They may cause a loss in biodiversity.
Choose all the characteristics of acute viral infections.
They often (although not always) establish at the site of infection. They involve rapid viral replication. They result in the sudden symptom onset.
What are knockout mice used for (choose all that apply)?
To identify during which developmental stage a gene functions To determine if a gene is essential for survival or not To determine the function of a gene
What is the function of the terminator in a transcriptional unit in bacteria?
To signal the end of transcription
Which of the following is a virus that has a helical capsid?
Tobacco mosaic
MicroRNAs and short-interfering RNAs regulate gene expression at what level?
Translation
What process involves the synthesis of a protein, and takes place on the ribosome?
Translation
____ which takes place on the ribosome, is the synthesis of protein from an RNA transcript.
Translation
Select ways in which the initiation of translation can be regulated.
Translation repressor proteins can block translation initiation. Translation factors can be modified.
Small RNAs likely evolved to protect the genome.
True
True or false: Even though we have little evidence, it is believed that the transport of mRNAs out of the nucleus is a potential site of gene regulation.
True Reason: We also know that half of the exons in primary transcripts never leave the the nucleus, indicating that transport of mRNA out of the nucleus might be regulated.
True or false: Several new techniques allow scientists to directly edit the genome of living cells.
True The TALE proteins and the CRISPR/Cas9 systems allow scientists to edit the genome of living cells.
Chromatin can be altered in a number of ways, such as histone modification and DNA methylation. When are such alterations considered to be epigenetic
When they are inherited through cell division When they persist in the absence of the initiation stimulus
Chromatin can be altered in a number of ways, such as histone modification and DNA methylation. When are such alterations considered to be epigenetic (choose all that apply)?
When they are inherited through cell division When they persist in the absence of the initiation stimulus
New combinations of the hemagglutinin (H) and neuraminidase (N) protein spikes arise in the influenza virus because genetic recombination can occur for which of the following reasons?
When two or more different influenza subtypes infect the same cell
Based on the nature of its genome and the way it is replicated, HIV is an example of
a retrovirus
Prokaryotes have
a single RNA polymerase Eukaryotes have three different RNA polymerases, which differ in function and structure. Prokaryotes only have one RNA polymerase. The polymerase can be found in two forms - the core enzyme and the holoenzyme - but they are still just different forms of the same single RNA polymerase.
When scientists synthesized an RNA molecule made of U (polyU) and translated it in cell-free translation systems, they produced a protein made of
a string of the same amino acid
An organism that carries a gene (or genes) from a different species that was introduced via genetic engineering, is called
a transgenic organism
The lac repressor binds to the lac operon when lactose is (present/absent) and the trp repressor binds to the trp operon when tryptophan is (present/absent).
absent present
Choose the two functional ends of a tRNA?
acceptor stem anticodon loop Codons are located on the mRNA, tRNA do not have codon loops, only an anticodon loop. There are initiator tRNAs which participate in the initiation of translation, however, tRNAs do not have initiator stems.
a(n) ______ viral infection involves the rapid replication of the virus, often at the site of infection, which leads to sudden symptom onset.
acute
Match the type of chromosomal mutation with its definition.
deletion - loss of portion of a chromosome duplication - copying a portion of a chromosome inversion - segment of chromosome is broken in 2 places, reversed, and put back together translocation - a piece of chromosome is broken off and joined to another chromosome
The two main eukaryotic DNA polymerases that extend DNA are
delta and epsilon
Hybridization allows scientists to
detect a specific DNA sequence in a complex mixture
The major significance of the Hershey and Chase's experiments is that they
determined that DNA is the genetic material
In order for mismatch repair to occur in a bacterial cell, the enzyme machinery must be able to
distinguish between the template strand and a newly synthesized strand.
in order for mismatch repair to occur in a bacterial cell, the enzyme machinery must be able to
distinguish between the template strand and a newly synthesized strand.
In their experiments, Avery, MacLeod, and McCarty isolated a substance, which had a transforming activity. Which of the following destroyed that substance's ability to transform bacterial cells? Multiple choice question.
dna digesting enzymes
The genetic material of viruses classified into Group III of the Baltimore classification is
double-stranded RNA
Small changes to the HA and NA genes of influenza viruses due to mutation are known as antigenic _______
drift
The ________ period occurs between the attachment and assembly stages in the bacteriophage reproductive cycle because cell lysis during that time will prevent the release of active virions.
eclipse
The time between adsorption and the formation of new viral particles is called which of the following?
eclipse period
Chemical modification of bases in the RNA to change their base-pairing properties (deamination of cytosine to uracil and deamination of adenine to inosine) are examples of RNA _______
editing
Bacteriophage exhibit two reproductive cycles: the _________ cycle, in which the latent phage is replicated with the host cell, and the _________ cycle, in which phage undergo replication within the host cell, eventually causing it to rupture.
lysogenic lytic
During which of the following reproductive cycles does a bacteriophage integrate its own DNA into the host cell's genome?
lysogenic cycle
The viral reproductive cycle that occurs when viral DNA is incorporated into and replicated with the infected host cell's genome is known as which of the following?
lysogenic cycle
A bacteriophage that integrates its own DNA into that of its host cell, allowing it to replicate with the host's genome is a(n) ______ phage
lysogenic or temperate
A bacteriophage that integrates its own DNA into that of its host cell, allowing it to replicate with the host's genome is a(n) ________phage.
lysogenic or temperate
In reverse transcription PCR
mRNA is used to produce millions of copies of its complementary DNA
Proteins can recognize specific base pair sequences in DNA without unwinding the double helix by interacting with the ____ ____ of the helix.
major groove
Proteins can recognize specific base pair sequences in DNA without unwinding the double helix by interacting with the _____ _____ of the helix
major groove
DNA primase (choose all that apply)
makes a primer of RNA complementary to the DNA. makes a primer about 10 -20 nucleotides in length.
Co-activators and ________ act by binding transcription factors and then binding another part of the transcription apparatus.
mediators
Ribosomes cannot directly process DNA to synthesize polypeptides; they can only translate a specific type of RNA transcript, the ____ RNA
messenger
In eukaryotes, an intermediate is needed to carry the information in DNA to the ribosome in the cytoplasm. This intermediate is
messenger mRNA
In order to study viruses in the environment, scientists isolate nucleic acids from an environmental sample, sequence them, and use computers to assemble genomes and compare them to known sequences in databases. This approach is known as ____
metagenomics
Which of the following RNA molecules act in post-transcriptional gene regulation?
miRNA siRNA Reason: rRNA molecules make up the ribosome together with many proteins and help catalyze the formation of the peptide bond. Reason: RISC is a protein complex. miRNA is loaded into RISC.
What type of repair mechanism is responsible for removing bases that were incorrectly inserted into DNA during replication?
mismatch repair
What type of mutation occurs when a base substitution results in a change of a single amino acid of a protein?
missense
____ mutation occurs when a base substitution leads to a change in one amino acid in the encoded protein.
missense
Transcription regulation in eukaryotes is how complex as compared to transcriptional regulation in prokaryotes?
much more
HIV is transmitted when contaminated bodily fluids come into contact with a _______ _______, or directly enter tissue
mucous membrane
Radiation, UV light, x-rays, and chemicals in the environment can cause mutations in DNA and are therefore referred to as
mutagens
HPV can transform a normal cell into a cancerous cell because the viral protein E7 binds the cell protein _______ and the viral protein E6 binds the cellular protein ______. These cellular proteins control cell growth and division.
pRb or Rb' p53
In ______ viral infections, a virus or its genome can be found in the host for long periods of time: years, decades, and sometime for the rest of the host's life.
persistant
A change in the phenotype of a lysogenic bacterium caused by the prophage is called ______ _____
phage conversion
In DNA, consecutive nucleotides are linked via ______ bonds, which are made between the 5' phosphate of one nucleotide and the 3' _______ group of another nucleotide.
phosphodiester hydroxyl or OH
Repeating sugar and phosphate units in a single DNA strand make up the
phosphodiester backbone.
Adjacent nucleotides in the same DNA strand are held together by covalent bonds known as ___ bonds.
phosphodiester or phosphoester
The enzyme _______ can repair UV damage by binding to a thymine dimer and cleaving it, therefore restoring two thymines.
photolyase
Of the following list, which 3 items are required for DNA replication
polymerase template nucleotides
Wastewater can be treated in two or three stages. The three stages are, in the order in which they are performed, ____, ______, and _____ treatment
primary secondary advanced
Telomerase uses which of the following as a template?
A short internal RNA
________ is an inherited disease and the patients with this disease produce urine that contains homogentisic acid
Alkaptonuria
Identify the physician who, in the early 1900s, proposed a relationship between genes and the production of enzymes.
Archibald Garrod
Consider the pathway for synthesis of arginine from glutamate by Neurospora crassa. A mutant for the argG gene will be able to grow on minimal media supplemented with which of the following (choose all that may apply)?
Arginosuccinate Arginine
Who determined that genes specify enzymes?
Beadle and Tatum
Who determined that genes specify enzymes? Multiple choice question.
Beadle and Tatum
Features of the Watson and Crick model include
a sugar phosphate backbone a double stranded structure a helical structure two grooves (major and minor)
In a DNA double helix, two hydrogen bonds form between
adenine and thymine
Which of the following facilitates the reversal of damage to our hereditary material before a permanent mutation can occur?
dna repair systems
