BIO 101 CH. 14 NVCC STUDY GUIDE
QUESTIONS WITH CORRECT
SOLUTIONS
When translating secretory or membrane proteins, ribosomes are directed to the ER
membrane by
A) a specific characteristic of the ribosome itself, which distinguishes free ribosomes
from bound ribosomes
B) a signal-recognition particle that brings ribosomes to a receptor protein in the ER
membrane
C) moving through a specialized channel of the nucleus
D) a chemical signal given off by the ER
E) a signal sequence of RNA that precedes the start codon of the message - ANSWER-
B) a signal-recognition particle that brings ribosomes to a receptor protein in the ER
membrane
What is the effect of a nucleotide-pair substitution that results in a nonsense mutation in
a gene?
A) It changes an amino acid in the encoded protein
B) It has no effect on the amino acid sequence of the encoded protein
C) It introduces a premature stop codon into the mRNA
D) It alters the reading frame of the mRNA - ANSWER-C) It introduces a premature stop
codon into the mRNA
Which of the following types of mutations could result in a frameshift mutation?
A) a base insertion only
B) a base deletion only
C) a base substitution only
D) deletion of three consecutive bases
E) either an insertion or a deletion of a base - ANSWER-E) either an insertion or a
deletion of a base
Which of the following DNA mutations is likely to have the most negative effect on 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 - ANSWER-A) a base-pair deletion
Which small-scale mutation would be most likely to have the greatest negative effect on
the functioning of a protein?
A) a base substitution
B) a base deletion near the start of a gene
C) a base deletion near the end of the coding sequence, but not in the terminator codon
D) deletion of three bases near the start of the coding sequence, but not in the initiator
codon
E) a base insertion near the end of the coding sequence, but not in the terminator codon
- ANSWER-B) a base deletion near the start of a gene
The most commonly occurring mutation in people with cystic fibrosis is a deletion of a
single codon. What is the most likely result of this mutation in the protein product?
A) a base-pair substitution
B) a nucleotide mismatch
C) a frameshift mutation
D) a polypeptide missing an amino acid
E) a nonsense mutation - ANSWER-D) a polypeptide missing an amino acid
Which of the following mutations is most likely to cause a phenotypic change?
A) a duplication of all or most introns
B) a nucleotide substitution in an exon coding for a transmembrane protein
C) a single nucleotide deletion in an exon coding for an active site of a protein
D) a frameshift mutation one codon away from the 3' end of the nontemplate strand -
ANSWER-C) a single nucleotide deletion in an exon coding for an active site of a
protein
Which of the following statements is true about protein synthesis in prokaryotes?
A) Extensive RNA processing is required before prokaryotic transcripts can be
translated
B) Translation can begin while transcription is still in progress
QUESTIONS WITH CORRECT
SOLUTIONS
When translating secretory or membrane proteins, ribosomes are directed to the ER
membrane by
A) a specific characteristic of the ribosome itself, which distinguishes free ribosomes
from bound ribosomes
B) a signal-recognition particle that brings ribosomes to a receptor protein in the ER
membrane
C) moving through a specialized channel of the nucleus
D) a chemical signal given off by the ER
E) a signal sequence of RNA that precedes the start codon of the message - ANSWER-
B) a signal-recognition particle that brings ribosomes to a receptor protein in the ER
membrane
What is the effect of a nucleotide-pair substitution that results in a nonsense mutation in
a gene?
A) It changes an amino acid in the encoded protein
B) It has no effect on the amino acid sequence of the encoded protein
C) It introduces a premature stop codon into the mRNA
D) It alters the reading frame of the mRNA - ANSWER-C) It introduces a premature stop
codon into the mRNA
Which of the following types of mutations could result in a frameshift mutation?
A) a base insertion only
B) a base deletion only
C) a base substitution only
D) deletion of three consecutive bases
E) either an insertion or a deletion of a base - ANSWER-E) either an insertion or a
deletion of a base
Which of the following DNA mutations is likely to have the most negative effect on 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 - ANSWER-A) a base-pair deletion
Which small-scale mutation would be most likely to have the greatest negative effect on
the functioning of a protein?
A) a base substitution
B) a base deletion near the start of a gene
C) a base deletion near the end of the coding sequence, but not in the terminator codon
D) deletion of three bases near the start of the coding sequence, but not in the initiator
codon
E) a base insertion near the end of the coding sequence, but not in the terminator codon
- ANSWER-B) a base deletion near the start of a gene
The most commonly occurring mutation in people with cystic fibrosis is a deletion of a
single codon. What is the most likely result of this mutation in the protein product?
A) a base-pair substitution
B) a nucleotide mismatch
C) a frameshift mutation
D) a polypeptide missing an amino acid
E) a nonsense mutation - ANSWER-D) a polypeptide missing an amino acid
Which of the following mutations is most likely to cause a phenotypic change?
A) a duplication of all or most introns
B) a nucleotide substitution in an exon coding for a transmembrane protein
C) a single nucleotide deletion in an exon coding for an active site of a protein
D) a frameshift mutation one codon away from the 3' end of the nontemplate strand -
ANSWER-C) a single nucleotide deletion in an exon coding for an active site of a
protein
Which of the following statements is true about protein synthesis in prokaryotes?
A) Extensive RNA processing is required before prokaryotic transcripts can be
translated
B) Translation can begin while transcription is still in progress
