Name: 
 

Chapter 17 Review



Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 

Which of the following represents a similarity between RNA and DNA?
a.
Both are double-stranded.
b.
the presence of uracil
c.
the presence of an OH group on the 2' carbon of the sugar
d.
nucleotides consisting of a phosphate, sugar, and nitrogenous base
e.
Both are found exclusively in the nucleus.
 

 2. 

The enzyme polynucleotide phosphorylase randomly assembles nucleotides into a polynucleotide polymer. You add polynucleotide phosphorylase to a solution of adenosine triphosphate and guanosine triphosphate. The resulting artificial mRNA molecule would have ____ possible different codons if the code involved two-base sequences and ____ possible different codons if the code involved three-base sequences.
a.
2; 3
b.
2; 4
c.
4; 8
d.
4; 16
e.
16; 64
 
 
Use the table of condons below to answer the following questions.

chpt17_files/i0040000.jpg
 

 3. 

What amino acid sequence will be generated, based on the following mRNA codon sequence?
5'AUG-UCU-UCG-UUA-UCC-UUG
a.
met-arg-glu-arg-glu-arg
b.
met-glu-arg-arg-gln-leu
c.
met-ser-leu-ser-leu-ser
d.
met-ser-ser-leu-ser-leu
e.
met-leu-phe-arg-glu-glu
 

 4. 

A peptide has the sequence NTD-phe-pro-lys-gly-phe-pro-CTD. Which of the following sequences in the coding strand of the DNA codes for this peptide?
a.
3' UUU-CCC-AAA-GGG-UUU-CCC
b.
3' AUG-AAA-GGG-TTT-CCC-AAA-GGG
c.
5' TTT-CCC-AAA-GGG-TTT-CCC
d.
5' GGG-AAA-TTT-AAA-CCC-ACT-GGG
e.
5' ACT-TAC-CAT-AAA-CAT-TAC-UGA
 

 5. 

The genetic code is essentially the same for all organisms. From this, one can logically assume all of the following except
a.
a gene from an organism could theoretically be expressed by any other organism.
b.
all organisms have a common ancestor.
c.
DNA was the first genetic material.
d.
the same codons in different organisms usually translate into the same amino acids.
e.
different organisms have the same number of different types of amino acids.
 

 6. 

Which of the following are transcribed from DNA?
a.
protein
b.
exons
c.
rRNA
d.
B and C only
e.
A, B, and C
 

 7. 

Which of the following is not a part of the eukaryotic transcription initiation complex?
a.
promoter
b.
RNA polymerase
c.
transcription factors
d.
snRNP
e.
TATA box
 

 8. 

Which of the following is least related to the other items?
a.
translation
b.
TATA box
c.
transcription
d.
template strand
e.
RNA polymerase II
 

 9. 

RNA polymerase moves along the template strand of DNA in the ____ direction, and adds nucleotides to the ____ end of the growing transcript.
a.
3' to 5'; 5'
b.
3' to 5'; 3'
c.
5' to 3'; 5'
d.
5' to 3'; 3'
 

 10. 

What are the coding segments of a stretch of eukaryotic DNA called?
a.
introns
b.
exons
c.
codons
d.
replicons
e.
transposons
 

 11. 

Once transcribed, eukaryotic mRNA typically undergoes substantial alteration that includes
a.
excision of introns.
b.
fusion into circular forms known as plasmids.
c.
linkage to histone molecules.
d.
union with ribosomes.
e.
fusion with other newly transcribed mRNA.
 

 12. 

Which of the following is (are) true of snRNPs?
a.
They are made up of both protein and RNA.
b.
They bind to splice sites at each end of the intron.
c.
They join together to form a large structure called the spliceosome.
d.
Only A and C are true.
e.
A, B, and C are true
 

 13. 

Alternative RNA splicing
a.
is a mechanism for increasing the rate of transcription.
b.
can allow the production of proteins of dramatically different sizes from a single mRNA.
c.
can allow the production of proteins of dramatically different amino acid sequences from a single mRNA.
d.
B and C only
e.
A, B, and C
 

 14. 

Which of the following is least related to the other items?
a.
snRNP
b.
triplet code
c.
wobble
d.
tRNA
e.
anticodon
 

 15. 

What is an anticodon part of?
a.
DNA
b.
tRNA
c.
mRNA
d.
a ribosome
e.
an activating enzyme
 

 16. 

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5' CCG-ACG 3' (mRNA). The following activated transfer RNA molecules (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form.

tRNA Anticodon
Amino Acid
GGC
Proline
CGU
Alanine
UGC
Threonine
CCG
Glycine
ACG
Cysteine
CGG
Alanine

The dipeptide that will form will be
a.
cysteine-alanine.
b.
proline-threonine.
c.
glycine-cysteine.
d.
alanine-alanine.
e.
threonine-glycine.
 

 17. 

The function of the ribosome in polypeptide synthesis is to
a.
hold mRNA and tRNAs together.
b.
catalyze the addition of amino acids from tRNAs to the growing polypeptide chain.
c.
move along the mRNA and eject tRNAs during the translocation process.
d.
A and B only
e.
A, B, and C
 

 18. 

Choose the answer that has these events of protein synthesis in the proper sequence.
1. An aminoacyl-tRNA binds to the A site.
2. A peptide bond forms between the new amino acid and a polypeptide chain.
3. tRNA leaves the P site, and the P site remains vacant.
4. A small ribosomal subunit binds with mRNA.
5. tRNA translocates to the P site.
a.
1, 3, 2, 4, 5
b.
4, 1, 2, 5, 3
c.
5, 4, 3, 2, 1
d.
4, 1, 3, 2, 5
e.
2, 4, 5, 1, 3
 

 19. 

Which of the following does not occur during the termination phase of translation?
a.
A termination codon causes the A site to accept a release factor.
b.
The newly formed polypeptide is released.
c.
A tRNA with the next amino acid enters the P site.
d.
The two ribosomal subunits separate.
e.
Translation stops.
 

 20. 

What is one function of a signal peptide?
a.
to direct an mRNA molecule into the cisternal space of the ER
b.
to bind RNA polymerase to DNA and initiate transcription
c.
to terminate translation of the messenger RNA
d.
to translocate polypeptides across the ER membrane
e.
to signal the initiation of transcription
 

 21. 

Which of the following is not related to ribosomal activity?
a.
A site
b.
spliceosome
c.
codon recognition
d.
peptide bond formation
e.
P site
 

 22. 

Which of the following statements are true about protein synthesis in prokaryotes?
a.
Translation can begin while transcription is still in progress.
b.
Extensive RNA processing is required before prokaryotic transcripts can be translated.
c.
Prokaryotic cells have complicated mechanisms for targeting proteins to the appropriate cellular organelles.
d.
Only A and B are true.
e.
A, B, and C are true.
 

 23. 

Which of the following DNA mutations is the most likely to be damaging to the protein it specifies?
a.
a base-pair deletion
b.
a codon substitution
c.
a substitution in the last base of a codon
d.
a codon deletion
e.
a point mutation
 



 
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