Chapter 5
Of the following enzymes, which are correctly matched with their function? To be marked correct, you'll need to select all correctly matched statements, as there may be more than one correct answer. - Primase, removes RNA primers - Ligase, covalently bonds adjacent Okazaki fragments - Helicase, relieves torsion stress as DNA unwinds - DNA polymerase III, builds most of the DNA on the leading and lagging strand
- Ligase, covalently bonds adjacent Okazaki fragments - DNA polymerase III, builds most of the DNA on the leading and lagging strand
How are RNA nucleotides different from DNA nucleotides? Select all true statements. - RNA nucleotides do not contain thymine. - RNA nucleotides lack phosphate. - RNA nucleotides use the sugar ribose, while DNA nucleotides do not. - RNA nucleotides incorporate pyrimidine nitrogen bases, while DNA nucleotides only incorporate purine nitrogen bases.
- RNA nucleotides do not contain thymine. - RNA nucleotides use the sugar ribose, while DNA nucleotides do not.
Put the following steps of protein synthesis in the order that they occur in a eukaryotic cell: Translation ends at a stop codon RNA polymerase transcribes mRNA from DNA Protein sequence is elongated Translation initiates mRNA is processed and travels to a ribosome - 5, 2, 4, 1, 3 - 2, 5, 4, 3, 1 - 2, 4, 3, 5, 1 - 4, 3, 2, 5, 1
2, 5, 4, 3, 1
The four types of DNA nucleotides are: - T, C, G, & U - A, T, C, & G - A, T, U, & C - A, T, G, & U
A, T, C & G
Which of the following is the correct mRNA sequence encoded by the DNA sequence: TAC GGT CAC TTC ACT? - GCA UUG ACA GGA GUC - ATG CCA GTG AAG TGA - UAC GGU CAC UUC ACU - AUG CCA GUG AAG UGA
AUG CCA GUG AAG UGA
Which of the following might result in a frameshift mutation? - Nitrous acid - Benzopyrene - 5-bromouracil
Benzopyrene
Genes can be silences by a process called DNA methylation. Which of the following compounds is a methyl group? - CO2 - OH - CH3 - COOH
CH3
______ removes primer, closes gaps, and repairs mismatches. - DNA Polymerase I - DNA Polymerase III - Helicase - Ligase - Primase - Topoisomerases
DNA Polymerase I
__________ function is adding bases to the DNA chain & proofreading. - DNA Polymerase I - DNA Polymerase III - Helicase - Ligase - Primase - Topoisomerases
DNA Polymerase III
Which statement about DNA replication is FALSE? - Because the two strands of parental DNA run in opposite directions, the new strands must be made in different ways. - DNA polymerase builds a new strand by adding DNA nucleotides one at a time. - DNA ligase adds nucleotides to the lagging strand. - The two strands of parental DNA are separated during DNA replication. - The lagging strand is made of a series of pieces that must be joined together to make a continuous strand.
DNA ligase adds nucleotides to the lagging strand.
The molecule that seals the gaps between the pieces of DNA in the lagging strand is: - the replication fork. - DNA ligase. - RNA. - the leading strand. - DNA polymerase.
DNA ligase.
During DNA replication, which enzyme is involved in proofreading to prevent the incorrect matching of nucleotides? - primase - DNA polymerase - ligase - helicase
DNA polymerase
RNA primers are removed from the leading and lagging strand by ________. - Helicase - DNA polymerase I - DNA polymerase III - Topoisomerase
DNA polymerase
Which enzyme is the main contributor to the development of spontaneous mutations? - RNA primase - Ligase - DNA polymerase - Helicase
DNA polymerase
In DNA replication, what is the main enzyme responsible for adding complementary nucleotides to the daughter strand while reading the parent strand? - Gyrase - DNA polymerase I - DNA polymerase III - Primase
DNA polymerase III
Which of the following is an example of a spontaneous mutation? - DNA polymerase III accidently mismatches a G to a T during Escherichia coli DNA replication, resulting in a silent mutation. - Human cells are exposed to X-rays for a prolonged period of time, leading to multiple DNA strand breaks. - Plasmodium vivax cells are exposed to ultraviolet radiation, leading to the formation of thymine dimers within the DNA sequence. - Yeast DNA is exposed to acridine dye, resulting in distortion of the DNA double helix.
DNA polymerase III accidently mismatches a G to a T during Escherichia coli DNA replication, resulting in a silent mutation.
Which of the following describes how 5-bromouracil might create a mutation? - It can replace the base thymine and can base pair with guanine rather than adenine. - It causes double-stranded breaks of the DNA. - It creates bulges in the DNA that must be repaired. - It can form thymine dimers.
It can replace the base thymine and can base pair with guanine rather than adenine.
What is the purpose of an anticodon? - It's a region on a DNA that binds to a complementary codon on mRNA to ensure the proper amino acid is added to a growing protein. - It's a region on a tRNA that binds to a complementary codon on mRNA to ensure the proper amino acid is added to a growing protein. - It's a region on an mRNA that binds to a complementary codon on rRNA to ensure the proper amino acid is added to a growing protein. - It's a region on an rRNA that binds to a complementary codon on tRNA to ensure the proper amino acid is added to a growing protein.
It's a region on a tRNA that binds to a complementary codon on mRNA to ensure the proper amino acid is added to a growing protein.
Which of the following conditions would allow for the active transcription of the lac operon? - Lactose present, glucose absent - The lac operon is transcribed constitutively. -Lactose present, glucose present -Lactose absent, glucose present
Lactose present, glucose absent
Post-transcriptional regulation allows cells to control gene expression by regulating how often mRNA is translated into protein. Which of the following is not an example of post-transcriptional regulation? - Small non-coding RNAs - Operons - Riboswitches - Controlling mRNA stability
Operons
Riboswitches are best defined as _________. - parts of mRNA that are not translated and act as pre-transcription regulators - parts of mRNA that are not translated and act as post-transcription regulators - parts of mRNA that block the first tRNA from entering into the "A" site of the ribosome - factors that block the ribosome from binding
Parts of mRNA that are not translated and act as post-transcription regulators
Which of the following enzymes is incorrectly matched with its function? - Helicase - unwinds DNA helix. - Polymerase I - copies DNA on the leading and lagging strands. - Ligase - forms phosphodiester bonds to seal nicks in the DNA backbone in the lagging strand. - Primase - lays down and builds RNA primers.
Polymerase I - copies DNA on the leading and lagging strands.
Primase lays down a short piece of _______ as a primer to start DNA replication. - DNA - RNA - Carbohydrate - Protein
RNA
What is the main enzyme required for transcription of a gene? - DNA gyrase - Helicase - DNA polymerase - RNA polymerase
RNA polymerase
Which of the following makes mRNA from the information stored in a DNA template? - Ribosomes - DNA polymerase - tRNA - RNA polymerase
RNA polymerase
The role of transcription factors is to signal ________. - the reverse transcriptase to the promoter region of the intended gene to be transcribed - DNA polymerase to the promoter region of the intended gene to be transcribed - RNA polymerase to the promoter region of the intended gene to be transcribed - the ribosome formation around the mRNA
RNA polymerase to the promoter region of he intended gene to be transcribed
What type of pre-transcriptional regulation is the most likely to turn off the production of a substance that is already plentiful? - Repressible operons - Riboswitches - Small, noncoding mRNAs - Inducible operons
Repressible operons
There are two nonstandard encoding amino acids _______ and ________. - Cysteine and lysine - Proline and glycine - Methionine and leucine - Selenocysteine and pyrrolysine
Selenocysteine and pyrrolysine
Which term is incorrectly matched with the provided definition? - Transformation - uptake of DNA from the environment - Transduction - introduction of new genetic material into a viral cell by a bacterial species - Conjugation - transfer of genetic material via a physical connection - Transposons - movable genetic elements that are also known as "jumping genes"
Transduction - introduction of new genetic material into a viral cell by a bacterial species
Which of the following types of RNA contains hairpin loops and is involved in carrying amino acids to the ribosome during translation? - Messenger RNA - Regulatory RNA - Ribosomal RNA - Transfer RNA - Primer RNA
Transfer RNA
Transposons, also known as "jumping genes," can have a wide-range effect on cells. Which of the following would not likely be an effect? - Transposons may change genetic sequences. - Transposons may introduce new genes. - Transposons may alter gene expression patterns. - Transposons can repair damaged DNA.
Transposons can repair damaged DNA.
You are testing a chemical that you suspect is a mutagen. You set up an AMES test, and for your control (without the mutagen added to the bacterial culture) you observed only a few colonies. After you added the mutagen to the test sample, you observed similar results to your control—only a few colonies grew. What can you conclude about the chemical? - Your chemical is mutagenic. - Your chemical is not mutagenic.
Your chemical is not mutagenic.
Two daughter cells are most likely to inherit which one of the following from the parent cell? - A change in a nucleotide in mRNA - A change in a nucleotide in tRNA - A change in a nucleotide in rRNA - A change in a nucleotide in DNA - A change in a protein
a change in a a nucleotide in DNA
Which of the following is considered a pre-transcriptional regulation and NOT a post-transcriptional regulation? - the rate of ribosome association with the mRNA - the rate of mRNA processing in eukaryotic cells - a repressed operon - messenger RNA stability
a repressed operon
In an inducible operon, what protein is used to turn off transcription by binding to the operator sequence? - a repressor protein - post-transcription protein - an inducible protein - an initiator protein
a repressor protein
A transposon that relies on an RNA intermediate is called __________. - an RNA dependent transposon - RNA polymerase - a retrotransposon - a reverse transcriptase
a retrotransposon
After translation, protein modifications are necessary for a final functioning product. Which of the following is NOT part of protein modification? - Addition of inorganic factors - Addition of organic factors - Trimming - Addition of a methionine
addition of a methionine
Which of the following is not associated with the DNA helix? - Phosphodiester bonds - Amino acids - Thymine - Complementary base pairing
amino acids
Which of the following is the product of transcription? - A polypeptide sequence - Multiple Okazaki fragments - An RNA sequence - A newly replicated strand of DNA
an RNA sequence
Quorum sensing allows bacteria within communities to communicate with chemical messages, which may help regulate gene expression. The chemical messages are called __________. - autorepressors - autoinducers - autofactors - autoregulators
autoinducers
Which of the following is NOT a method of horizontal gene transfer? - binary fission - conjugation - integration of transposon - transduction - transformation
binary fission
A nucleotide- altering chemical: - can alter nitrogenous bases of DNA, resulting in incorrect base pairing. - can cause double-stranded breaks in the DNA. - can slip in between stacked bases, causing bulges in the DNA structure. - can be incorporated into the DNA, to cause a mispairing of bases.
can alter nitrogenous bases of DNA, resulting in incorrect base pairing.
If a cell is to be transformed in a lab, the cell must be ________ to uptake the available genetic information. - Competent - Exposed to a virus - Equipped with a pilus - Killed
competent
The exchange of genetic information by use of a pilus and cell to cell interaction is called _______. - Transduction - Conjugation - Transformation - Transposons
conjugation
During optimum conditions, E. coli will replicate every 20 minutes. Because the genes required for replication are needed as part of a routine function, these genes are considered? - facultative genes - constitutive genes - repressible genes - operator genes
constitutive genes
The term redundancy in molecular biology refers to __________. - Different codons that code for the same amino acid - Repressing the expression of a gene - The multiple sites to being DNA replication - Overexpression of a gene
different codons that code for the same amino acid
Which of the following is not directly involved in protein synthesis? - tRNA - rRNA - mRNA - dsRNA
dsRNA
In DNA replication, protein factors are more heavily required for replication in ________. - Eukaryotic cells - Prokaryotic cells - Both eukaryotic and prokaryotic cells - In neither
eukaryotic cells
The process of removing incorrect nucleotides and replacing them with correct ones is referred to as __________. - Excision repair - Replication repair - Base substitution - Mutation correction
excision repair
Which of the following mutations is the most detrimental to the cell? - silent mutation - nonsense mutation - frameshift mutation - missense mutation
frameshift mutation
The genetic makeup of an organism is its: - phenotype - chromosome - genotype - karyotype
genotype
__________ unzips the DNA helix. - DNA Polymerase I - DNA Polymerase III - Helicase - Ligase - Primase - Topoisomerases
helicase
The Ames test is used to identify if a chemical will result in mutations. This test uses the microorganism S. typhimurium and the amino acid _______. - Glycine - Histidine - Lysine - Proline
histidine
The process of transferring of genetic information between cells in the same generation is referred to as __________. - Asexual reproduction - Vertical gene transfer - Sexual reproduction - Horizontal gene transfer
horizontal gene transfer
Mutagens ___________. - decrease the likelihood of mutations in DNA. - increase the likelihood of mutations in DNA. - come in two basic forms: ionizing and nonionizing radiation. - are the sole cause of mutations in DNA.
increase the likelihood of mutations in DNA
An operon that is transcribed in response to the presence of a substrate is called a(n) _______. - constitutive operon - inducible operon - promoter - repressible operon
inducible operon
In eukaryotic mRNA, there are sequences of mRNA that do NOT encode for specific amino acids and do NOT contribute to the protein. These sequences are called _________. - Promoters - Okazaki fragments - Introns - Exons
introns
mRNA _______. - serves as a molecule to carry amino acids to the ribosome during translation - is translated to build proteins - contains deoxyribose - combines with proteins to build ribosomes
is translated to build proteins
Of the following statements, which does NOT apply to microorganism that has a fertility plasmid? - It can further develop into a Hfr cell. - It has a pilus. - It can undergo vertical gene transfer. - It can undergo horizontal gene transfer.
it can undergo vertical gene transfer
Which of the following conditions would allow for the active transcription of the lac operon? - Lactose present, glucose absent - The lac operon is transcribed constitutively - Lactose present, glucose present - Lactose absent, glucose present
lactose present, glucose absent
____________ is the final binding of nicks in DNA during synthesis and repair. - DNA Polymerase I - DNA Polymerase III - Helicase - Ligase - Primase - Topoisomerases
ligase
Which of the following can be translated into protein? - mRNA - rRNA - mRNA, tRNA, and rRNA are all translated into protein. - tRNA
mRNA
Transcription produces which of the following? - mRNA - rRNA - tRNA - mRNA and tRNA - mRNA and rRNA - mRNA, tRNA, and rRNA are all produced by transcription.
mRNA, tRNA, and rRNA are all produced by transcription.
Thymine dimers result from __________. - nucleoside analogs. - mistakes by DNA polymerase. - ionizing radiation. - nonionizing radiation.
nonionizing radiation.
Where is the chromosomal DNA found in prokaryotic cells? - Ribosome - Nucleoid - Nucleus - Nucleolus
nucleoid
Genes that are essential for survival of a bacterial cell would most likely be located _______. - in the nucleus - on a histone - on the chromosome(s) - on a plasmid
on the chromosomes
In an operon, the repressor binds to the _______. - promoter - inducer - operator - genes
operator
Post-transcriptional regulation allows cells to control gene expression by regulating how often mRNA is translated into protein. Which of the following is not an example of post-transcriptional regulation? - Operons - Riboswitches - Controlling mRNA stability - Small non-coding RNAs
operons
Which functional group is found at the 5' end of DNA? - Phosphate group - Carboxyl group - Methyl group - Hydroxyl group
phosphate group
Which type of genetic material may be found in both prokaryotic and eukaryotic cells and may contain genes conferring antibiotic resistance? - chromosomal DNA - mitochondrial DNA - plasmids - chloroplast
plasmids
Which of the following statements is NOT a characteristic of plasmids? - Plasmids are involved in horizontal gene transfer. - Plasmids are part of the cell's chromosome. - Plasmids carry genes that may be involved in antibiotic resistance. - Plasmids replicate independently of the cell's chromosome.
plasmids are part of the cells membranes
_________ functions as synthesizing an RNA primer: - DNA Polymerase I - DNA Polymerase III - Helicase - Ligase - Primase - Topoisomerases
primase
to start DNA replication, the origin of replication is recognized by a collection of factors called the ________. - Primosome - RNA primer - Okazaki fragments - Single-strand binding proteins
primosome
One major difference between prokaryotic and eukaryotic translation is _________. - Prokaryotic translation required more protein factors than eukaryotic translation - Prokaryotic translation involves polysomes, while eukaryotic translation does not - Prokaryotic translation requires more protein factors than eukaryotic translation - Prokaryotic translation is polycistronic, and eukaryotic translation is almost always monocistronic.
prokaryotic translation is polycistronic, and eukaryotic translation is almost always monocistronic
Ribosomes contain which of the following? - mRNA, tRNA, and rRNA are all found as part of the ribosome. - mRNA - tRNA - rRNA
rRNA
cDNA is a product of the action of _______. - DNA polymerase - Transferase - RNA polymerase - Reverse transcriptase
reverse tanscriptase
RNA nucleotides are made of a sugar, a phosphate, and a nitrogen base. Which sugar is unique to RNA nucleotides and NOT found in DNA nucleotides? - Fructose - Glucose - Deoxyribose - Ribose
ribose
Which of the following is not needed during transcription? - Ribosomes - Ribonucleotides - RNA polymerase - DNA template
ribosomes
Transduction that involves a temperate phage integrating into the host cell genome is called __________. - Generalized transduction - Localized transduction - Specialized transduction - Exchange transduction
specialized transduction
Which of the following would not be a component of an operon? - start codon - structural genes - promoter - operator
start codon
An anticodon is found on _______. - DNA - rRNA - mRNA - tRNA
tRNA
Which of the following is involved in bringing amino acids to the ribosomes? - mRNA - tRNA - mRNA, tRNA, and rRNA are all involved in transporting amino acids to the ribosomes. - rRNA
tRNA
Which type of RNA carries in amino acids and adds the amino acids to the "A" site in the ribosome? - cRNA - rRNA - mRNA - tRNA
tRNA
The term used by molecular biologist to describe the flow of genetic information from DNA, to RNA, to protein is ___________. - Translation - Transcription - Gene expression - The central dogma of biology
the central dogma of biology
In DNA replication, Okazaki fragments are required in synthesizing _________. - The leading strand, because the DNA polymerase can move only in the 5' to 3' direction - The lagging strand, because the DNA polymerase can move only in the 5' to 3' direction - Both strands, because the fragments provide a starting point for DNA polymerase - The origin of replication
the lagging strand, because the DNA polymerase can only move in the 5' to 3' direction
Which of the following would be considered a FALSE statement about small noncoding RNAs? - They are found only in prokaryotic cells. - They are used in post-transcription regulation. - They can be used to tag a ribosome to be destroyed. - They reduce the amount of protein made from mRNA.
they are only found in prokaryotic cells
Of the following statements, which one is NOT related to transposable elements? - They recombine the genome. - They create a stable, non-changing genome. - They require the transposase enzyme. - They can change the rate of gene expression.
they create a stable, non-changing genome
A codon consists of _______ nucleotides. - Two - Three - Four - Five
three
UV radiation can result in _______ in a cells DNA. - Thymine dimers - Nonsense mutations - Silent mutations - Frameshift mutations
thymine dimers
_______ is for untangling during DNA replication - DNA Polymerase I - DNA Polymerase III - Helicase - Ligase - Primase - Topoisomerases
topoisomerases
Which of the following mechanisms of horizontal transfer involves the transfer of bacterial DNA through a bacteriophage? - Transposition - Conjugation - Transformation - Transduction - None of the above
transduction
Griffith's experiment proved that bacteria can take up naked DNA from the environment and use it as part of their genome. This process, which can occur in a lab or in a natural setting, is called ________. - Transposition - Transformation - Conjugation - Transduction
transformation
Transfer of DNA from a donor to a recipient as naked DNA in solution is _______. - Conjugation - Transcription - Transduction - Transformation - Translation
transformation
Which of the following nucleotides is found only in RNA and not in DNA? - Uracil - Adenine - Cytosine - Guanine
uracil
Proteins provide cells with the necessary equipment to perform normal cellular activity. Without gene expression the cell _______. - Would still be able to reproduce - Would still be able to metabolize substrates - Would die - Could function with minimal capabilities
would die
