WorksheetsGenetics and Molecular Biology Worksheet
Total questions: 83
Worksheet time: 42mins
Eukaryotic transcription differs from prokaryotic in that
eukaryotes have only one RNA polymerase.
eukaryotes have three RNA polymerases.
prokaryotes have three RNA polymerases.
Both a and c are correct.
The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?
The same codons in different organisms translate into different amino acids.
A gene from an organism can theoretically be expressed by any other organism.
DNA was the first genetic material.
Different organisms have different types of amino acids.
The figure above shows a simple metabolic pathway. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway?
1
2
3
It cannot be determined from the pathway.
Refer to the metabolic pathway illustrated above. If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on a medium supplemented with.
nutrient A only
nutrient B only
nutrient C only
nutrients A and C nutrient
Refer to the metabolic pathway illustrated above. If A, B, and C are all required for growth, a strain mutant for the gene-encoding enzyme B would be able to grow on a medium supplemented with.
nutrient A only
nutrient B only
nutrient C only
nutrients A and C
A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be _____
AAA-AAT-ATA-ACA
TTG-CTA-CAG-TAG
AAA-GAA-TAA-CAA
AUG-CTG-CAG-TAT
What would the anticodon be for a tRNA that transports phenylalanine to a ribosome?
AAA
UUU
TTT
CCC
Which of the following contradicts the one-gene, one-enzyme hypothesis?
Alkaptonuria results when individuals lack a single enzyme involved in the catalysis of homogentisic acid.
A single antibody gene can code for different related proteins, depending on the splicing that takes place post-transcriptionally.
A mutation in a single gene can result in a defective protein.
Sickle-cell anemia results in defective hemoglobin.
In the process of transcription, ____.
mRNA attaches to ribosomes
DNA is replicated
proteins are synthesized
RNA is synthesized
Codons are part of the molecular structure of ____.
tRNA
mRNA
rRNA
a protein
What does it mean when we say the genetic code is redundant?
A) A single codon can specify the addition of more than one amino acid.
B) More than one codon can specify the addition of the same amino acid.
C) The genetic code is universal (the same for all organisms).
D) The genetic code is different for different domains of organisms.
According to the central dogma, what molecule should go in the blank? DNA → ____ → Proteins
mRNA
tRNA
mtDNA
rRNA
How do eukaryotic codons and prokaryotic codons compare?
The translation of codons is mediated by tRNAs in eukaryotes, but translation requires no intermediate molecules such as tRNAs in prokaryotes.
Prokaryotic codons usually specify different amino acids than those of eukaryotes.
Prokaryotic codons usually contain different bases than those of eukaryotes.
Codons are a nearly universal language among all organisms.
Which of the following does not occur in prokaryotic gene expression, but does occur in eukaryotic gene expression?
RNA polymerase requires a primer to elongate the molecule.
RNA polymerase binds to the promoter.
A cap is added to the 5' end of the mRNA.
mRNA, tRNA, and rRNA are transcribed.
Alternative RNA splicing _____
increases the rate of transcription
can allow the production of proteins of different sizes and functions from a single mRNA
is a mechanism for increasing the rate of translation
can allow the production of similar proteins from different RNAs
A ribozyme is _____
an enzyme that synthesizes RNA as part of the transcription process
a catalyst that uses RNA as a substrate
an RNA with catalytic activity
an enzyme that catalyzes the association between the large and small ribosomal subunits
A primary transcript in the nucleus of a eukaryotic cell is _____ the functional mRNA, while a primary transcript in a prokaryotic cell is _____ the functional mRNA.
larger than; the same size as
larger than; smaller than
the same size as; larger than
the same size as; smaller than
Translation requires _____
mRNA, DNA, and rRNA
mRNA, tRNA, and DNA
mRNA, tRNA, DNA, and rRNA
mRNA, tRNA, and rRNA
How does termination of translation take place?
The poly-A tail is reached.
The 5' cap is reached.
A stop codon is reached.
The end of the mRNA molecule is reached.
Which of the following statements is true about protein synthesis in prokaryotes?
Prokaryotic cells have complicated mechanisms for targeting proteins to the appropriate cellular organelles.
Unlike eukaryotes, prokaryotes require no initiation or elongation factors.
Extensive RNA processing is required before prokaryotic transcripts can be translated.
Translation can begin while transcription is still in progress.
A signal peptide _____
helps target a protein to the ER
directs an mRNA molecule into the cisternal space of the ER
terminates translation of messenger RNA
signals the initiation of transcription
What amino acid sequence will be generated, based on the following mRNA codon sequence? 5' AUG-UCU-UCG-UUA-UCC-UUG 3'
met-arg-glu-arg-glu-arg
met-glu-arg-arg-glu-leu
met-ser-ser-leu-ser-leu
met-ser-leu-ser-leu-ser
What is the Central Dogma Theory in biology?
DNA --> mRNA --> Proteins --> Traits
Proteins --> mRNA --> DNA --> Traits
mRNA --> DNA --> Proteins --> Traits
Traits --> Proteins --> mRNA --> DNA
Before transcription begins, what must happen first?
Modification of mRNA
DNA replication
Translation of mRNA
Splicing of introns
A promoter is ________.
Special sequence to which DNA polymerase binds to
Special sequence to which RNA polymerase binds to
Special sequence to which cDNA polymerase binds to
Special sequence to which mRNA polymerase binds to
In prokaryotes, transcription ends in the presence of a ________ Terminator.
Terminator
Promoter
Enhancer
Operator
In eukaryotes, transcription ends in the presence of __________.
Poly A tail
Ribosome binding site
Shine-Dalgarno sequence
Start codon
In translation, mRNA is converted to _______, which takes place in the _______ of a cell.
proteins, cytoplasm/cytosol
lipids, nucleus
carbohydrates, mitochondria
DNA, nucleolus
Based on question 6, in what organelle is mRNA converted to polypeptide chain(s)?
Ribosomes
Nucleus
Mitochondria
Golgi apparatus
What is the most commonly known start codon?
AUG - codes for methionine
UAA - codes for stop
UAG - codes for stop
UGA - codes for stop
Translation ends with the presence of a __________ codon.
UAG, UGA, UAA
AUG, GUG, UGG
CAA, GAA, AAA
GCU, GCC, GCA
What molecule in the spliceosome lowers the activation energy so intron removal reactions can occur?
autocatalysis by introns
ribozymes
proteins of the spliceosome
RNA polymerase
Which of the following does not occur in post-transcriptional modifications occurring in eukaryotic mRNAs?
addition of a poly (A) tail
RNA polymerase termination
removal of introns
addition of a methyl-guanosine cap
There should be a strong positive correlation between the rate of protein synthesis and _____
the number of ribosomes
the quantity of DNA polymerase
the size of mRNA
the quantity of RNA polymerase
Ribosomes can attach to prokaryotic messenger RNA _____
once post-transcriptional modification is complete
once replication is complete
before transcription is complete
once the primary transcript has been released from RNA polymerase
Which of the following occurs in prokaryotes, but not eukaryotes?
gene regulation
post-transcriptional splicing
translation in the absence of a ribosome
concurrent transcription and translation
Refer to Figure 16.3. What is the function of the CUC on the loop of the tRNA?
It is the active site of this ribozyme.
It stabilizes the tRNA-amino acid complex.
It attaches to the amino acid.
It base pairs with the codon of mRNA.
How does the termination of translation take place?
The 5' cap is reached.
A stop codon is reached.
The end of the mRNA molecule is reached.
The poly-A tail is reached.
A mutation that results in premature termination of translation _____
is a nonsense mutation
is a missense mutation
usually has no effect on the function of the protein
is a silent mutation
A ribozyme is _____
an RNA with catalytic activity
an enzyme that synthesizes RNA as part of the transcription process
a catalyst that uses RNA as a substrate
an enzyme that catalyzes the association between the large and small ribosomal subunits
an enzyme that synthesizes RNA primers during DNA replication
Refer to the figure above. The mRNA is smaller than the length of the DNA that codes for it because _____
post-transcriptional modification removes the introns
bases are added to the tail of the primary transcript
the regulatory regions (exons) of the gene are not transcribed
post-transcriptional modification removes the exons
If the DNA code for a particular amino acid is 5' AGT 3', then the anticodon on the tRNA would be _____
5' UCA 3'
5' AGU 3'
5' TCA 3'
5' ACU 3'
Translation requires _____
mRNA, DNA, and tRNA
mRNA, tRNA, and DNA
Which of the following are the three major types of RNA?
mRNA, tRNA, and DNA
mRNA, tRNA, and snRNA
mRNA, tRNA, and rRNA
mRNA, tRNA, DNA, and rRNA
Transcription in eukaryotes requires which of the following in addition to RNA polymerase?
several transcription factors
aminoacyl-tRNA synthetase
start and stop codons
the protein product of the promoter
ribosomes and tRNA
What is a ribozyme?
an enzyme that uses RNA as a substrate
an enzyme that synthesizes RNA as part of the transcription process
an enzyme that synthesizes RNA primers during DNA replication
an enzyme that catalyzes the association between the large and small ribosomal subunits
an RNA with enzymatic activity
Alternative RNA splicing,
can allow the production of proteins of different sizes and functions from a single mRNA.
is a mechanism for increasing the rate of transcription.
increases the rate of transcription.
is due to the presence or absence of particular snRNPs.
can allow the production of similar proteins from different RNAs.
What molecules in the spliceosome catalyze the intron removal reactions?
introns
tRNA
RNA polymerases
ribozymes
What is the effect of a nonsense mutation in a gene?
It introduces a premature stop codon into the mRNA.
It changes an amino acid in the encoded protein.
It prevents introns from being excised.
It has no effect on the amino acid sequence of the encoded protein.
It alters the reading frame of the mRNA.
Which one of the following, if missing, would prevent transcription from starting?
exon
poly-A tail
5' cap
AUG codon
The lac operon is controlled by two main proteins. These proteins _____
Both act in a negative fashion.
Both act in a positive fashion.
Act in the opposite fashion, one negative and one positive.
Act at the level of translation.
In eukaryotes, binding of RNA polymerase to a promoter requires the action of ______.
Specific transcription factors.
General transcription factors.
Repressor proteins.
Inducer proteins.
The lac repressor, the trp repressor, and CAP are all ______.
Negative regulators of transcription.
Positive regulators of transcription.
Allosteric proteins that bind to DNA and an effector.
Proteins that can bind DNA or other proteins.
Eukaryotic mRNAs differ from prokaryotic mRNAs in that they _______.
Usually contain more than one gene.
Are colinear with the genes that encode them.
Are not colinear with the genes that encode them.
Both a and c are correct.
An example of a promotor would be ________.
ATAT Box
TATA Box
UAUA Box
TATA promotor
What molecule that will be present and cause the operon to allow transcription to occur?
repressor
inducer
operon
operator
The experiments with nutritional mutants in Neurospora by Beadle and Tatum provided evidence that _______.
bread mold can be grown in a lab on minimal media.
X-rays can damage DNA.
cells need enzymes.
genes specify enzymes.
What is the central dogma of molecular biology?
DNA is the genetic material.
Information passes from DNA directly to protein.
Information passes from DNA to RNA to protein.
One gene encodes only one polypeptide.
In the genetic code, one codon
consists of three bases.
specifies a single amino acid.
specifies more than one amino acid.
Both a and b are correct.
An anticodon would be found on which of the following types of RNA?
snRNA (small nuclear RNA)
tRNA (transfer RNA)
mRNA (messenger RNA)
rRNA (ribosomal RNA)
RNA polymerase binds to a _________ to initiate _________.
mRNA ; translation
promoter ; transcription
primer ; transcription
transcription factor ; translation
During translation, the codon in mRNA is actually "read" by
the A site in the ribosome.
the anticodon in a tRNA.
the P site in the ribosome.
the anticodon in an amino acid.
Which of the following is used to make complementary DNA (cDNA) from RNA?
reverse transcriptase
DNA ligase
gene cloning
gel electrophoresis
restriction enzymes
Why are yeast cells frequently used as hosts for cloning?
They are eukaryotes
Only yeast cells allow the gene to be cloned.
They do not have plasmids.
Which of the following best describes the complete sequence of steps occurring during every cycle of PCR?
1. The primers hybridize to the target DNA
2. The mixture is heated to a high temperature to denature the double-stranded target DNA
3. Fresh DNA polymerase is added
4. DNA polymerase extends the primers to make a copy of the target DNA
A) 2, 1, 4
B) 2, 3, 4
C) 3, 4, 2
D) 1, 3, 2, 4
E) 3, 4, 1, 2
Small circular, extrachromosomal DNA segments are known as _________.
plasmids
chromosomes
ribosomes
introns
Single-stranded complementary tails that are produced by restriction digestion are called ________ ends.
5'
orphaned
vectors
sticky
Two strands of DNA that have been cut by an endonuclease can be sealed together by a(n)?
exonuclease enzyme.
protease enzyme.
polymerase enzyme.
ligase enzyme.
The PCR technique requires a DNA polymerase from an organism that can endure high heat, such as Thermus aquaticus. What step of the protocol makes the heat-stability most necessary?
A) Antibody binding
B) Primer annealing
C) Synthesis
D) Denaturation
Organisms containing DNA from an outside source are called?
compound organisms.
transgenic organisms.
plasmid organisms.
transcribed organisms.
hybrid organisms.
The reason for using Taq polymerase for PCR is that 6) ________
it is heat-stable and can withstand temperature changes of the cycler
it is a human enzyme
it is sensitive to low temperatures
it inhibits DNA synthesis
They can remove exons from mRNA.
They are eukaryotic cells.
They can add nucleotides to the 5' end of mRNA.
They can synthesize DNA from RNA templates.
They can splice introns from tRNA.
Which of the following is a property of Taq polymerase that makes it especially useful in PCR?
it is heat stable and can withstand the temperature changes of the cycler.
only minute amounts are needed for each cycle of PCR.
it binds more readily than other polymerases to primer.
All of these are correct.
Assume that you are trying to insert a gene into a plasmid. Someone gives you a preparation of genomic DNA that has been cut with restriction enzyme X. The gene you wish to insert has sites on both ends for cutting by restriction enzyme Y. You have a plasmid with a single site for Y, but not for X. Your strategy should be to 1)_____
cut the DNA again with restriction enzyme Y and insert these fragments into the plasmid cut with the same enzyme.
cut the plasmid restriction enzyme X and then insert the gene into the plasmid.
insert the fragments cut with restriction enzyme X directly into the plasmid without cutting the plasmid.
cut the plasmid twice with restriction enzyme Y and ligate the two fragments onto the ends of the DNA fragments cut with restriction enzyme X.
A principal problem with inserting an unmodified mammalian gene into a BAC, and then getting that gene expressed in bacteria, is that
bacterial DNA is not found in a membrane-bounded nucleus and is therefore incompatible with mammalian DNA
bacteria cannot remove eukaryotic introns
bacterial RNA polymerase cannot make RNA complementary to mammalian DNA
prokaryotes use a different genetic code from that of eukaryotes
Which enzyme was used to produce the molecule in Figure 20.1
a restriction enzyme
RNA polymerase
DNA polymerase
ligase
A eukaryotic gene has "sticky ends" produced by the restriction endonuclease EcoRI. The gene is added to a mixture containing EcoRI and a bacterial plasmid that carries two genes conferring resistance to ampicillin and tetracycline. The plasmid has one recognition site for EcoRI located in the tetracycline resistance gene. This mizture is incubated for seceral hours, exposed to DNA ligasem and the added to bacteria growing in nutrient broth. The bacteria are allowed to grow overnight and are streaked on a plate using a technique that produces isolated colonies that are clones of the original. Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient broth plus ampicillin and tetracycline, and nutrient broth without antibiotics.
BBACTERIA THAT DO NOT TAKE UP ANY PLASMIDS WOULD GROW ON WHICH MEDIA
the nutrient broth and ampicillin broth
the nutrient broth and tetracycline broth
the tetracycline broth and the ampicillin broth
the nutrient broth only
Enzymes that cleave DNA at specific sites are called___
DNAses
Vectors
Peptidases
Restriction Endonucleases
An enzyme that has been isolated from retroviruses and is used to generate cDNA is ___
Reverse endonuclease
Transverse ligase
RNA polymerase
Reverse transcriptase
Both DNA replication and PCR require:
a thermocycler machine
DNA polymerase
plasmid DNA
DNA template
The PCR technique requires a DNA polymerase from an organism that can endure high heat, such as Thermus aquaticus. What step of the protocol makes the heat-stability most necessary?
Antibody binding
primer annealing
denaturation
synthesis
Refer to the figure above. What would the anticodon be for a tRNA that transports phenlyalanine to a ribosome?
AAA
UUU
TTT
CCC
Codons are three-base sequences that specify the addition of a single amino acid. How do eukaryotic codons and prokaryotic codons compare?
Codons are a nearly universal language among all organisms.
prokaryotic codons usually contain different bases than those of eukaryotes
prokaryotic codons usually specify different amino acids than those of eukaryotes
