Genetics Final Exam Review UPDATED
ACTUAL Exam Questions and CORRECT
Answers
nearly universal. - CORRECT ANSWER - The genetic code is:
A. ambiguous.
B. overlapping.
C. not degenerate.
D. nearly universal.
there are more codons than there are amino acids. - CORRECT ANSWER - Which of the
following is true?
A. every amino acid is coded for by a single codon.
B. there are more codons than there are amino acids.
C. every codon codes for an amino acid.
D. some codons in a gene code for more than one single amino acid.
initiation codon - CORRECT ANSWER - AUG is almost always the:
A. intron
B. exon
C. initiation codon
D. anticodon
degeneracy - CORRECT ANSWER - What property of the genetic code allows the use of
several codons for a particular amino acid?
,A. near universality
B. degeneracy
C. non-overlapping codons
D. reading frame
The introns have been spliced out during mRNA processing. - CORRECT ANSWER - It
has been recently determined that the gene for Duchenne muscular dystrophy (DMD) is more
than 2000 kb (kilobases) in length, however, the mRNA produced by this gene is only about 14
kb long. What is a likely cause of this discrepancy?
A. The exons have been spliced out during mRNA processing.
B. The DNA represents a double-stranded structure, whereas the RNA is single-stranded.
C. There are more amino acids coded for by the DNA than by the mRNA.
D. The introns have been spliced out during mRNA processing.
low glucose, high lactose - CORRECT ANSWER - In the lac operon, under which of the
following conditions will the lac genes be transcribed at high levels?
A. low glucose, low lactose
B. high glucose, low lactose
C. low glucose, high lactose
D. high glucose, high lactose
the repressor would not be bound - CORRECT ANSWER - Use the following diagram of
the lac operon for questions 8-10:
(I = lac repressor gene, Z, Y, A = lac operon structural genes, P = lac promoter, O = lac operator)
Where would the lac repressor normally be bound in an E. coli cell that is growing in low
glucose and high lactose?
,A. P
B. O
C. P and O
D. the repressor would not be bound
P,O - CORRECT ANSWER - Use the following diagram of the lac operon for questions 8-
10:
(I = lac repressor gene, Z, Y, A = lac operon structural genes, P = lac promoter, O = lac operator)
Which parts of the DNA region shown in the diagram above do not code for proteins?
A. Z, Y, A
B. I,P,O,
C. P,O
D. They all code for proteins
Z, Y, A - CORRECT ANSWER - Use the following diagram of the lac operon for
questions 8-10:
(I = lac repressor gene, Z, Y, A = lac operon structural genes, P = lac promoter, O = lac operator)
Which protein coding sequences are transcribed together on one single mRNA?
A. Z, Y, A
B. P, O, Z, Y, A
C. I, Z, Y, A
D. I, P, O, Z, Y, A
, positive and negative control - CORRECT ANSWER - The ara operon is controlled by a
regulator protein that exerts ________.
A. expressivity and penetrance
B. positive and negative control
C. upward and reverse control
D. paralogous and orthologous
tryptophan is a co-repressor. - CORRECT ANSWER - With regards to the trp operon,
A. tryptophan is an inducer.
B. tryptophan is a co-repressor.
C. attenuation can halt replication.
D. none of the above.
when there is no tryptophan in the medium, transcription of the trp operon occurs at high levels. -
CORRECT ANSWER - Under the system of genetic control of the trp operon,
A. when there are high levels of tryptophan in the medium, transcription of the trp operon
occurs at high levels.
B. when there is no tryptophan in the medium, transcription of the trp operon
occurs at high levels.
C. when there are high levels of tryptophan in the medium, transcription of CAP
occurs at high levels.
D. when there are high levels of tryptophan in the medium, ribosomes "stall" and
reduce the levels of tryptophan synthesized.
alteration in the folded structure of an mRNA upon binding of a protein or other ligand. -
CORRECT ANSWER - In the regulation of gene expression, a "riboswitch" involves
ACTUAL Exam Questions and CORRECT
Answers
nearly universal. - CORRECT ANSWER - The genetic code is:
A. ambiguous.
B. overlapping.
C. not degenerate.
D. nearly universal.
there are more codons than there are amino acids. - CORRECT ANSWER - Which of the
following is true?
A. every amino acid is coded for by a single codon.
B. there are more codons than there are amino acids.
C. every codon codes for an amino acid.
D. some codons in a gene code for more than one single amino acid.
initiation codon - CORRECT ANSWER - AUG is almost always the:
A. intron
B. exon
C. initiation codon
D. anticodon
degeneracy - CORRECT ANSWER - What property of the genetic code allows the use of
several codons for a particular amino acid?
,A. near universality
B. degeneracy
C. non-overlapping codons
D. reading frame
The introns have been spliced out during mRNA processing. - CORRECT ANSWER - It
has been recently determined that the gene for Duchenne muscular dystrophy (DMD) is more
than 2000 kb (kilobases) in length, however, the mRNA produced by this gene is only about 14
kb long. What is a likely cause of this discrepancy?
A. The exons have been spliced out during mRNA processing.
B. The DNA represents a double-stranded structure, whereas the RNA is single-stranded.
C. There are more amino acids coded for by the DNA than by the mRNA.
D. The introns have been spliced out during mRNA processing.
low glucose, high lactose - CORRECT ANSWER - In the lac operon, under which of the
following conditions will the lac genes be transcribed at high levels?
A. low glucose, low lactose
B. high glucose, low lactose
C. low glucose, high lactose
D. high glucose, high lactose
the repressor would not be bound - CORRECT ANSWER - Use the following diagram of
the lac operon for questions 8-10:
(I = lac repressor gene, Z, Y, A = lac operon structural genes, P = lac promoter, O = lac operator)
Where would the lac repressor normally be bound in an E. coli cell that is growing in low
glucose and high lactose?
,A. P
B. O
C. P and O
D. the repressor would not be bound
P,O - CORRECT ANSWER - Use the following diagram of the lac operon for questions 8-
10:
(I = lac repressor gene, Z, Y, A = lac operon structural genes, P = lac promoter, O = lac operator)
Which parts of the DNA region shown in the diagram above do not code for proteins?
A. Z, Y, A
B. I,P,O,
C. P,O
D. They all code for proteins
Z, Y, A - CORRECT ANSWER - Use the following diagram of the lac operon for
questions 8-10:
(I = lac repressor gene, Z, Y, A = lac operon structural genes, P = lac promoter, O = lac operator)
Which protein coding sequences are transcribed together on one single mRNA?
A. Z, Y, A
B. P, O, Z, Y, A
C. I, Z, Y, A
D. I, P, O, Z, Y, A
, positive and negative control - CORRECT ANSWER - The ara operon is controlled by a
regulator protein that exerts ________.
A. expressivity and penetrance
B. positive and negative control
C. upward and reverse control
D. paralogous and orthologous
tryptophan is a co-repressor. - CORRECT ANSWER - With regards to the trp operon,
A. tryptophan is an inducer.
B. tryptophan is a co-repressor.
C. attenuation can halt replication.
D. none of the above.
when there is no tryptophan in the medium, transcription of the trp operon occurs at high levels. -
CORRECT ANSWER - Under the system of genetic control of the trp operon,
A. when there are high levels of tryptophan in the medium, transcription of the trp operon
occurs at high levels.
B. when there is no tryptophan in the medium, transcription of the trp operon
occurs at high levels.
C. when there are high levels of tryptophan in the medium, transcription of CAP
occurs at high levels.
D. when there are high levels of tryptophan in the medium, ribosomes "stall" and
reduce the levels of tryptophan synthesized.
alteration in the folded structure of an mRNA upon binding of a protein or other ligand. -
CORRECT ANSWER - In the regulation of gene expression, a "riboswitch" involves
