1.
Who was the first person to isolate the material that came to be known as nucleic acids?
a. Frederick Griffith
b. Friedrich Miescher
c. James Watson
d. Oswald Avery
2.
What is bacterial transformation?
a. The transformation of a bacterium occurs during replication.
b. It is the transformation of a bacterium into a pathogenic form.
c. Transformation of bacteria involves changes in its chromosome.
d. Transformation is a process in which external DNA is taken up by a cell, thereby
changing morphology and physiology.
3.
What type of nucleic acid material is analyzed the most frequently in forensics cases?
a. cytoplasmic rRNA
b. mitochondrial DNA
c. nuclear chromosomal DNA
d. nuclear mRNA
4.
The experiments by Hershey and Chase helped confirm that DNA was the hereditary
material on the basis of the finding of what?
a. Radioactive phages were found in the pellet.
b. Radioactive cells were found in the supernatant.
c. Radioactive sulfur was found inside the cell.
d. Radioactive phosphorus was found in the cell.
5.
If DNA of a particular species was analyzed and it was found that it contains 27%27% A,
what would be the percentage of C?
a. 23%23%
b. 27%27%
c. 30%30%
d. 54%54%
6.
If the sequence of the 5’ to 3’ strand is AATGCTAC, then the complementary sequence has
the following sequence:
a. 3’-AATGCTAC-5’
b. 3’-CATCGTAA-5’
c. 3’-TTACGATG-5’
d. 3’-GTAGCATT-5’
7.
The DNA double helix does not have which of the following?
a. antiparallel configuration
b. complementary base pairing
c. major and minor grooves
d. uracil
8.
What is a purine?
a. a double ring structure with a six-membered ring fused to a five-membered ring
b. a single six-membered ring
c. a six-membered ring
d. three phosphates covalently bonded by phosphodiester bonds
9.
What is the name of the method developed by Fred Sanger to sequence DNA?
a. dideoxy chain termination method
b. double helix determination
c. polymerase chain reaction
d. polymer gel electrophoresis
10.
What happens when a dideoxynucleotide is added to a developing DNA strand?
a. The chain extends to the end of the DNA strand.
b. The DNA strand is duplicated.
c. The chain is not extended any further.
d. The last codon is repeated.
11.
In eukaryotes, what is DNA wrapped around?
a. histones
b. polymerase
c. single-stranded binding proteins
d. sliding clamp
12.
Which enzyme is only found in prokaryotic organisms?
a. DNA gyrase
b. helicase
c. ligase
d. telomerase
13.
Uracil is found where?
a. chromosomal DNA
b. helicase
c. mitochondrial DNA
d. mRNA
14.
What prevents the further development of a DNA strand in Sanger sequencing?
a. the addition of DNA reductase
b. the addition of dideoxynucleotides
c. the elimination of DNA polymerase
d. the addition of uracil
15.
Which of the following is not involved during the formation of the replication fork?
a. helicase
b. ligase
c. origin of replication
d. single-strand binding proteins
16.
In which direction does DNA replication take place?
a. 5’ to 3’
b. 3’ to 5’
c. 5’
d. 3’
17.
Meselson and Stahl’s experiments proved that DNA replicates by which model?
a. conservative
b. converse
c. dispersive
d. semi-conservative
18.
Which set of results was found in the Meselson and Stahl’s experiments?
a. The original chromosome was kept intact and a duplicate was made.
b. The original chromosome was split and half went to each duplicate.
c. The original chromosome was mixed with new material and each duplicate strand
contained both old and new.
d. The original chromosome was used as a template for two new chromosomes and
discarded.
19.
Which enzyme initiates the splitting of the double DNA strand during replication?
a. DNA gyrase
b. helicase
c. ligase
d. telomerase
20.
Which enzyme is most directly responsible for the main process of producing a new DNA
strand?
a. DNA polymerase I
b. DNA polymerase II
c. DNA polymerase III
d. DNA polymerase I, DNA polymerase II, and DNA polymerase III
21.
Which portion of a chromosome contains Okazaki fragments?
a. helicase
b. lagging strand
c. leading strand
d. primer
22.
Which of the following does the enzyme primase synthesize?
a. DNA primer
b. Okazaki fragments
c. phosphodiester linkage
d. RNA primer
23.
The ends of the linear chromosomes are maintained by what?
a. DNA polymerase
b. helicase
c. primase
d. telomerase
24.
What is the difference in the rate of replication of nucleotides between prokaryotes and
eukaryotes?
a. Eukaryotes are 5050 times slower.
b. Eukaryotes are 2020 times faster.
c. Prokaryotes are 100100 times slower.
d. Prokaryotes are 1010 times faster.
25.
What are autonomously replicating sequences (ARS)?
a. areas of prokaryotic chromosomes that initiate copying
b. portions of prokaryotic chromosomes that can be transferred from one organism to
another
c. areas of eukaryotic chromosomes that are equivalent to the origin of replication
in E. coli
d. portions of eukaryotic chromosomes that replicate independent of the parent
chromosome
26.
What type of body cell does not exhibit telomerase activity?
a. adult stem cells
b. embryonic cells
c. germ cells
d. liver cells
27.
During proofreading, which of the following enzymes reads the DNA?
a. DNA polymerase
b. helicase
c. topoisomerase
d. primase
28.
If a prokaryotic cell is replicating nucleotides at a rate of 100100 per second, how fast
would a eukaryotic cell be replicating nucleotides?
a. 10001000 per second
b. 100100 per second
c. 1010 per second
d. 11 per second
29.
Which type of point mutation would have no effect on gene expression?
a. frameshift
b. missense
c. nonsense
d. silent
30.
Which type of point mutation would result in the substitution of a stop codon for an amino
acid?
a. frameshift
b. missense
c. nonsense
d. silent
31.
You have developed a mutation that leads to skin cancer and you are pregnant. You are
worried that your child will be born with the cancer mutation you have while carrying the
baby. Should you be worried?
a. Yes, the cancer can spread to the baby.
b. No, the mutations causing the cancer are in somatic cells, not reproductive germ
cells.
c. Yes, the mutations can be passed on to the child through the placenta.
d. No, UV light only affects adult, somatic cells.
32.
What is the initial mechanism for repairing nucleotide errors in DNA?
a. DNA polymerase proofreading
b. mismatch repair
c. nucleotide excision repair
d. thymine dimers
33.
Nucleotide excision repair is often employed when UV exposure causes the formation of
what?
a. phosphodiester bonds
b. purine conjugates
c. pyrimidine dimers
d. tetrad disassembly
1.
What is the flow of information for the synthesis of proteins according to the central
dogma?
a. DNA to mRNA to protein
b. DNA to mRNA to tRNA to protein
c. DNA to protein to mRNA to protein
d. mRNA to DNA to mRNA to protein
2.
The DNA of virus A is inserted into the protein coat of virus B. The combination virus is used
to infect E. coli. The virus particles produced by the infection are analyzed for DNA and
protein contents. What results would you expect?
a. DNA and protein from B
b. DNA and protein from A
c. DNA from A and protein from B
d. DNA from B and protein from A
3.
The AUC and AUA codons in mRNA both specify isoleucine. What feature of the genetic
code explains this?
a. complementarity
b. degeneracy
c. nonsense codons
d. universality
4.
How many nucleotides are in 12 mRNA codons?
a. 1212
b. 2424
c. 3636
d. 4848
5.
Which of the following molecules does not contain genetic information?
a. DNA
b. mRNA
c. protein
d. RNA
6.
Which molecule in the central dogma can be compared to a disposable photocopy of a
book kept on reserve in the library?
a. DNA
b. mRNA
c. Protein
d. tRNA
7.
Which subunit of the E. coli polymerase confers specificity to transcription?
a. αα
b. β
c. ββ’
d. σσ
8.
Why are the −10−10 and −35−35 regions of prokaryotic promoters called consensus
sequences?
a. They are identical in all bacterial species.
b. They are similar in all bacterial species.
c. They exist in all organisms.
d. They have the same function in all organisms.
9.
The sequence that signals the end of transcription is called the ______________.
a. promoter
b. stop codon
c. TATA box
d. terminator
10.
If the ρρ protein is missing, will a prokaryotic gene be terminated?
a. It depends on the gene.
b. No, the rho protein is essential.
c. Transcription termination is not required.
d. Yes, the rho protein is not involved in transcription.
11.
Which feature of promoters can be found in both prokaryotes and eukaryotes?
a. GC box
b. octamer box
c. TATA box
d. -10 and -35 sequences
12.
At what stage in the transcription of a eukaryotic gene would TFII factors be active?
a. elongation
b. initiation
c. processing
d. termination
13.
Which polymerase is responsible for the synthesis of 5S rRNA?
a. polymerase I
b. polymerase II
c. polymerase III
d. ribonuclease I
14.
What transcripts will be most affected by low levels of αα-amanitin?
a. 18S and 28S rRNAs
b. 5S rRNAs and tRNAs
c. other small nuclear RNAs
d. pre-mRNAs
15.
Which of the following features distinguishes eukaryotic transcription from bacterial
transcription?
a. Eukaryotic transcription does not start at a consensus sequence.
b. Eukaryotic transcription does not require an initiation complex.
c. Eukaryotic transcription and translation do not take place at the same time.
d. Eukaryotic transcription does not require a termination sequence.
16.
A poly-A sequence is added at the _______________.
a. 5’ end of a transcript in the nucleus
b. 3’-end of a transcript in the nucleus
c. 5’ end of a transcript in the cytoplasm
d. 3’-end of a transcript in the cytoplasm
17.
Which pre-mRNA processing step is important for initiating translation?
a. poly-A tail
b. RNA editing
c. splicing
d. 7-methylguanosine cap
18.
Where are the RNA components of ribosomes synthesized?
a. cytoplasm
b. endoplasmic reticulum
c. nucleus
d. nucleolus
19.
What processing step enhances the stability of pre-tRNAs and pre-rRNAs?
a. cleavage
b. methylation
c. nucleotide modification
d. splicing
20.
What are introns?
a. DNA sequences to which polymerases bind
b. the processed mRNA
c. translated DNA sequences in a gene
d. untranslated DNA sequences in a gene
21.
What is often the first amino acid added to a polypeptide chain?
a. adenine
b. leucine
c. methionine
d. thymine
22.
In any given species, there are at least how many types of aminoacyl tRNA synthetases?
a. 2020
b. 4040
c. 100100
d. 200200
23.
In prokaryotic cells, ribosomes are found in/on the _______________.
a. cytoplasm
b. mitochondrion
c. nucleus
d. endoplasmic reticulum
24.
The peptide bond synthesis in prokaryotic translation is catalyzed by ____________.
a. a ribosomal protein
b. a cytoplasmic protein
c. mRNA itself
d. ribosomal RNA
25.
What would happen if the 5’ methyl guanosine was not added to an mRNA?
a. The transcript would degrade when the mRNA moves out of the nucleus to the
cytoplasm.
b. The mRNA molecule would stabilize and start the process of translation within the
nucleus of the cell.
c. The mRNA molecule would move out of the nucleus and create more copies of the
mRNA molecule.
d. The mRNA molecule would not be able to add the poly-A tail on its strand at the 5’
end.
26.
Which of the following is associated with the docking of mRNA on a ribosome in eukaryotic
cells?
a. Kozak’s sequence
b. poly-A sequence
c. Shine-Dalgarno sequence
d. TATA box
1.
Control of gene expression in eukaryotic cells occurs at which level(s)?
a. only the transcriptional level
b. epigenetic and transcriptional levels
c. epigenetic and transcriptional and translational levels
d. epigenetic and transcriptional, translational, and post-translational levels
2.
What do figures X and Y in the graphic illustrate?
a. Transcription and translation in a eukaryotic cell (figure X) and a prokaryotic cell
(figure Y).
b. Transcription and translation in a prokaryotic cell (figure X) and a eukaryotic cell
(figure Y).
c. Transcription in a eukaryotic cell (figure X) and translation in a prokaryotic cell
(figure Y).
d. Transcription in a prokaryotic cell (figure X) and translation in a eukaryotic cell
(figure Y)
3.
Reformat to indicate that answer completes stem: "If glucose is absent but lactose is
present, the lac operon will be____________."
a. activated
b. repressed
c. partially activated
d. mutated
4.
What would happen if the operator sequence of the lac operon contained a mutation that
prevented the repressor protein from binding the operator?
a. In the presence of lactose, the lac operon will not be transcribed.
b. In the absence of lactose, the lac operon will be transcribed.
c. The cAMP-CAP complex will not increase RNA synthesis.
d. The RNA polymerase will not bind the promoter.
5.
What would happen if the operator sequence of the trp operon contained a mutation that
prevented the repressor protein from binding to the operator?
a. In the absence of tryptophan, the genes trpA-E will not be transcribed.
b. In the absence of tryptophan, only genes trpE and trpD will be transcribed.
c. In the presence of tryptophan, the genes trpA-E will be transcribed.
d. In the presence of tryptophan, the trpE gene will not be transcribed.
6.
What are epigenetic modifications?
a. the addition of reversible changes to histone proteins and DNA
b. the removal of nucleosomes from the DNA
c. the addition of more nucleosomes to the DNA
d. mutation of the DNA sequence
7.
Which of the following statements about epigenetic regulation is false?
a. Histone protein charge becomes more positive when acetyl groups are added.
b. DNA molecules are modified within CpG islands.
c. Methylation of DNA and histones causes nucleosomes to pack tightly together.
d. Histone acetylation results in the loose packing of nucleosomes.
8.
Which of the following is true of epigenetic changes?
a. They only allow gene expression.
b. They allow movement of histones.
c. They change the DNA sequence.
d. They are always heritable.
9.
The binding of what is required for transcription to start?
a. a protein
b. DNA polymerase
c. RNA polymerase
d. a transcription factor
10.
What would be the outcome of a mutation that prevented DNA bending proteins from being
produced?
a. decreased transcription because transcription factors would not bind to
transcription binding sites
b. decreased transcription because enhancers would not be able to bind to
transcription factors
c. increased transcription because repressors would not be able to bind to promoter
regions
d. increased transcription because RNA polymerase would be able to increase binding
to promoter regions
11.
What will result from the binding of a transcription factor to an enhancer region?
a. decreased transcription of an adjacent gene
b. increased transcription of a distant gene
c. alteration of the translation of an adjacent gene
d. initiation of the recruitment of RNA polymerase
12.
Which of the following are involved in post-transcriptional control?
a. control of RNA splicing
b. ubiquitination
c. proteolytic cleavage
d. phosphorylation
13.
Gene A is thought to be associated with color blindness. The protein corresponding to gene
A is isolated. Analysis of the protein recovered shows there are actually two different
proteins that differ in molecular weight that correspond to gene A. What is one reason why
there may be two proteins corresponding to the gene?
a. One protein had a 5’ cap and a poly-A tail in its mRNA, and the other protein did not.
b. One protein had a 5’ UTR and a 3’ UTR in its RNA, and the other protein did not.
c. The gene was alternatively spliced.
d. The gene produced mRNA molecules with differing stability.
14.
Binding of an RNA binding protein will change the stability of the RNA molecule in what
way?
a. increase it
b. decrease it
c. neither increase nor decrease it
d. either increase or decrease it
15.
A mutation in the 5’UTR that prevents any proteins from binding to the region
will_____________.
a. increase or decrease the stability of the RNA molecule
b. prevent translation of the RNA molecule
c. prevent splicing of the RNA molecule
d. increase or decrease the length of the poly-A tail
16.
Post-translational modifications of proteins can affect which of the following?
a. mRNA splicing
b. 5’capping
c. 3’polyadenylation
d. chemical modifications
17.
A mutation is found in eIF-2 that impairs the initiation of translation. The mutation could
affect all but one of the following functions of eIF-2. Which one would not be affected?
a. The mutation prevents eIF-2 from binding to RNA.
b. The mutation prevents eIF-2 from being phosphorylated.
c. The mutation prevents eIF-2 from binding to GTP.
d. The mutation prevents eIF-2 from binding to the 40S ribosomal subunit.
18.
The addition of a ubiquitin group to a protein does what?
a. increases the stability of the protein
b. decreases translation of the protein
c. increases translation of the protein
d. marks the protein for degradation
19.
What are cancer-causing genes called?
a. transformation genes
b. tumor suppressor genes
c. oncogenes
d. protooncogenes
20.
Targeted therapies are used in patients with a certain gene expression pattern. A targeted
therapy that prevents the activation of the estrogen receptor in breast cancer would be
beneficial to what type of patient?
a. patients who express the EGFR receptor in normal cells
b. patients with a mutation that inactivates the estrogen receptor
c. patients with over-expression of ER alpha in their tumor cells
d. patients with over-expression of VEGF, which helps in tumor angiogenesis
21.
In a new cancer treatment, a cold virus is genetically modified so that it binds to, enters,
and is replicated in cells, causing them to burst. The modified cold virus cannot replicate
when wildtype p53 protein is present in the cell. How does this treatment treat cancer
without harming healthy cells?
a. The modified virus only infects and enters cancer cells.
b. The modified virus replicates in normal and cancer cells.
c. The modified virus only infects and enters normal cells.
d. The modified virus replicates only in cancer cells.
22.
A drug designed to switch silenced genes back on in cancer cells would do what?
a. prevent methylation of DNA and deacetylation of histones
b. prevent methylation of DNA and acetylation of histones
c. prevent deacetylation of DNA and methylation of histones
d. prevent acetylation of DNA and demethylation of histones
23.
What is the name given to positive cell-cycle regulators that can cause cancer when
mutated?
a. transformation genes
b. tumor suppressor genes
c. oncogenes
d. mutated genes
