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1.
What type of replication results in one duplex containing both parental strands
and the other duplex containing two new strands of DNA after the two parental
strands had served as templates for the two daughter strands?
A. Semiconservative replication.
B. Conservative replication.
C. Dispersive replication.
D. Incisive replication.
E. Reservative replication.
2.
Mutants whose deficiencies are observed at high temperatures, but not at lower
temperatures, are called ________ mutants.
A. Temperature-resistant.
B. Temperature-sensitive.
C. Frameshift.
D. Point.
E. Deletions.
3.
_________ are sites where the pair of replicated segments come together and
join the nonreplicated segments.
A. Origins.
B. Replicons.
C. Replication forks.
D. Initiators.
E. Initiation forks.
4.
What directly supplies the energy for the action of DNA gyrase?
A. GTP hydrolysis.
B. ATP hydrolysis.
C. ATP condensation.
D. GTP condensation.
E. Proton gradient.
5.
In which direction does DNA polymerase move along the template?
A. 3’â>5′
B. Nâ>N
C. 5’â>3′
D. Câ>N
E. Nâ>C
6.
The enzyme that joins the Okazaki fragments of the lagging strand together into
a continuous strand is called _______.
A. DNA gyrase.
B. DNA ligase.
C. DNA polymerase.
D. Primase.
E. Deoxyribonuclease.
7.
What part of the DNA polymerase III holoenzyme is responsible for keeping the
DNA polymerase associated with the template strand over long stretches, while
allowing it to remain attached loosely enough to the template to allow its
movement from one nucleotide to the next?
A. The-pleated sheet.
B. The clamp loader.
C. The clamp.
D. The clamp.
E. The clamp.
8.
Replicons are the ______________.
A. Small portions of the genome in
which specific genes are located.
B. Small portions in which
eukaryotic cells replicate their genomes.
C. Small portions in which
prokaryotic cells replicate their genomes.
D. Small portions in which
prokaryotic cells transcribe their genomes.
E. Small portions in which
eukaryotic cells transcribe their genomes.
9.
Which of the following events directly triggers the initiation of replication
at an ARS?
A. The departure of the ARS.
B. The binding of other proteins
to the ORC-origin complex.
C. The departure of the ORC from
the ARS.
D. The binding of the ORC.
E. The changing of the ARS into an
ORC.
10.
Licensing factors ____________.
1) Bind to the ORC.
2) Aid in the assembly of a prereplication complex that is competent to
initiate replication.
3) Are generally Mcm proteins.
4) Aid in the assembly of a prereplication complex that is competent to
initiate translation.
A. 1
B. 2
C. 3
D. 4
E. 1, 2 and 3
11.
What types of destructive forces in the internal and external environments of
an organism cannot alter the structure of DNA?
A. Ionizing radiation can break
DNA backbone.
B. Exposure to a variety of
reactive chemicals, some made by cell metabolism, can structurally alter DNA
bases.
C. Ultraviolet radiation causes
adjacent pyrimidines to interact covalently, forming a dimer.
D. Absorption of electrical energy
generated by metabolism in a warm-blooded bird or mammal can split adenine
and guanine from their attachment to DNA backbone sugars.
E. All of these are correct.
12.
What enzyme removes the sugar-phosphate remnant that had been attached to the
excised base during base excision repair?
A. An AP endonuclease.
B. Phosphodiesterase activity of
DNA polymerase .
C. 5’â>3′ exonuclease.
D. 3’â>5′ exonuclease.
E. DNA glycosylase.
13.
What type of radiation is associated with xeroderma pigmentosum?
A. Infrared radiation.
B. Ultraviolet radiation.
C. Microwave radiation.
D. Radio waves.
E. X-rays.
14.
Translation is the ___________.
A. Synthesis of DNA from an RNA
template.
B. Synthesis of RNA from a DNA
template.
C. Synthesis of proteins from an
mRNA template.
D. Synthesis of proteins from an
rRNA template.
E. Synthesis of DNA from a DNA
template.
15.
The nonstandard base pairs of RNAs and their modified nitrogenous bases form
unorthodox regions of these molecules that serve ___________.
A. As recognition sites for proteins.
B. As recognition sites for other
RNAs.
C. To promote RNA folding.
D. To help stabilize the structure
of the molecule.
E. All of these are correct.
16.
The RNA polymerase moves along the DNA template strand in a ________ direction.
A. 3’â> 5′
B. 5’â> 3′
C. N terminal â> C terminal.
D. C terminal â> N terminal.
E. 5′ â> C terminal.
17.
Attachment of the factor _________.
1) Increases the core enzymes affinity for DNA in general.
2) Increases the core enzyme’s affinity for DNA promoter sites.
3) Decreases the core enzyme’s affinity for DNA promoter sites.
4) Decreases the core enzyme’s affinity for DNA in general.
A. 1
B. 2
C. 3
D. 4
E. 2 and 4
18.
Which of the following is a normal property of eukaryotic mRNAs?
A. They contain a continuous
nucleotide sequence encoding a specific polypeptide.
B. All of the other answers.
C. They are attached to ribosomes
when they are translated.
D. Most have a significant
noncoding segment that does not direct the assembly of amino acids.
E. Eukaryotic mRNAs have special
modifications at their 5′ and 3′ termini.
19.
Why are hnRNAs much larger than the mature mRNAs derived from them?
1) Exons in hnRNAs are much larger than the introns in those same hnRNAs.
2) Introns in hnRNAs are much larger than the exons in those same hnRNAs.
3) Introns are removed from hnRNAs as they are processed to make mature RNAs.
A. 1
B. 2
C. 3
D. 1 and 3
E. 2 and 3
20.
Alternative splicing explains _____________.
A. Why genes are so long.
B. How one gene can code for more
than one polypeptide.
C. How many genes can code for the
same protein.
D. How RNA can also serve as an
enzyme.
E. How DNA can be rearranged.
21.
Both plants and animals produce hundreds of tiny RNAs that are relatively small
in size (roughly 21 â 24 nucleotides in length). First discovered in nematodes,
they are synthesized only at certain times during development, or in certain
tissues of a plant or animal, and are presumed to play a regulatory role. They
are called ________.
1) tRNAs.
2) siRNAs.
3) microRNAs.
4) miRNAs.
A. 1
B. 2
C. 3
D. 4
E. 3 and 4
22.
You travel to another planet and discover that its genetic system is based on
DNA, but it has 8 bases instead of 4 as happens on Earth. The proteins on the
planet have 56 amino acids. What would be the likely number of letters in each
codon on this planet?
A. 1
B. 2
C. 3
D. 4
E. 6
23.
Translation __________.
A. Is the assembly of RNA on a DNA
template.
B. Is the assembly of DNA on an
RNA template.
C. Is the assembly of an amino
acid polymer by a ribosome directed by the sequence of bases in Mrna.
D. Is the assembly of an amino
acid polymer by a ribosome directed by the sequence of bases in rRNA.
E. Is the assembly of a nucleic
acid polymer by a ribosome directed by the sequence of bases in mRNA.
24.
When and how is the CCA on the end of every tRNA added in many prokaryotes?
A. A single enzyme adds the three nucleotides
in the proper order without a DNA or RNA template.
B. It is added by RNA polymerase
II.
C. It is added after translation
enzymatically.
D. It is added before
transcription but after processing enzymatically.
E. They are encoded in the tRNA
gene and added during transcription.
25.
According to the rules of the wobble hypothesis, which of the following codons
could pair with the anticodon 3′-CAI-5′?
1) 5′-GUU-3′
2) 3′-GUU-5′
3) 5′-GUC-3′
4) 5′-GUA-3′
A. 1
B. 2
C. 3
D. 4
E. 1, 3 and 4
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