BIO II EXAM 2 PRACTICE QUESTIONS
The study of Neurospora mutants grown on various supplemented media led to:
a. a determination of the steps in biological pathways.
b. the one-gene, one-enzyme hypothesis.
c. the idea that genes are "on" chromosomes.
d. Both a and b
e. Both a and c - Answers- D
The transfer of information from DNA to RNA occurs during _______, while the transfer
of information from RNA to protein occurs during _______.
a. translation; transcription
b. translation; elongation
c. translation; transvection.
d. transcription; translation
e. transcription; transvection - Answers- D
The "central dogma" of molecular biology states that:
a. information flow between DNA, RNA, and protein is reversible.
b. information flow in the cell is unidirectional, from protein to DNA.
c. information flow in the cell is unidirectional, from DNA to protein.
d. the DNA sequence of a gene can be predicted if we know the amino acid sequence
of the
protein it encodes.
e. the genetic code is ambiguous but not degenerate. - Answers- C
Which of the following is not required for transcription?
a. A DNA template
b. A primer
c. Ribonucleoside triphosphates
d. RNA polymerase
e. All of the above are required for transcription. - Answers- B
In prokaryotes, the region of DNA to which RNA polymerase binds most tightly is the
a. promoter.
b. poly C center.
c. enhancer.
d. operator site.
e. minor groove. - Answers- A
,RNA polymerase is:
a. an RNA-directed DNA polymerase.
b. an RNA-directed RNA polymerase.
c. a form of RNA.
d. a ribozyme.
e. a DNA-directed RNA polymerase. - Answers- E
A codon is _______ nucleotides long, and there are _______ different possible codons
in total.
a. 2; 16
b. 2; 64
c. 3; 16
d. 3; 64
e. 4; 64 - Answers- D
The stop codons code for
a. no amino acid.
b. methionine.
c. glycine.
d. halt enzyme.
e. DNA binding protein. - Answers- A
The amino acids in proteins are encoded by _______ different codons.
a. 20
b. 23
c. 42
d. 61
e. 64 - Answers- D
Which of the following would be an example of an ambiguous genetic code?
a. One with 61 codons for 20 amino acids
b. One in which UUU and UUA both code for phenylalanine
c. One in which CCU could code for either alanine or leucine
d. All of the above
e. None of the above - Answers- C
Humans share the same genetic code with:
a. just other vertebrates.
b. just other multicellular animals.
c. just other multicellular animals and plants.
d. just other eukaryotes.
, e. all known life. - Answers- E
Aside from using T instead of U, the "coding strand" of DNA is _______ to the mRNA.
a. identical in sequence
b. identical in sequence but antiparallel
c. complementary and parallel
d. complementary and antiparallel
e. complementary and in a random order - Answers- A
The adaptor between mRNA and a protein is:
a. tRNA.
b. a promoter.
c. RNA polymerase.
d. DNA polymerase.
e. DNA. - Answers- A
In eukaryotic cells, translation occurs in the _______ and transcription occurs _______.
a. nucleus; in the nucleus
b. nucleus; in the cytoplasm
c. cytoplasm; in the nucleus
d. nucleus; outside of the cell
e. cytoplasm; outside of the cell - Answers- C
One can argue that although the existence of retroviruses represents a complication of
Crick's central dogma, it does not violate its spirit. The replication mechanism of
retroviruses does not contradict the essence of the central dogma because:
a. retroviruses convert DNA information into RNA information.
b. retroviruses convert RNA information into RNA information.
c. even in retroviruses, information in proteins is not converted into DNA information.
d. even in retroviruses, DNA information is not converted into protein information.
e. retroviruses do not use tRNA. - Answers- C
In a nucleic acid hybridization experiment performed to detect exons, the probe
a. single-stranded DNA.
b. double-stranded DNA.
c. triple-stranded DNA.
d. single-stranded RNA.
e. double-stranded RNA. - Answers- D
When eukaryotic DNA is hybridized with mRNA, the hybrid molecules contain loops of
double-stranded DNA, which are
The study of Neurospora mutants grown on various supplemented media led to:
a. a determination of the steps in biological pathways.
b. the one-gene, one-enzyme hypothesis.
c. the idea that genes are "on" chromosomes.
d. Both a and b
e. Both a and c - Answers- D
The transfer of information from DNA to RNA occurs during _______, while the transfer
of information from RNA to protein occurs during _______.
a. translation; transcription
b. translation; elongation
c. translation; transvection.
d. transcription; translation
e. transcription; transvection - Answers- D
The "central dogma" of molecular biology states that:
a. information flow between DNA, RNA, and protein is reversible.
b. information flow in the cell is unidirectional, from protein to DNA.
c. information flow in the cell is unidirectional, from DNA to protein.
d. the DNA sequence of a gene can be predicted if we know the amino acid sequence
of the
protein it encodes.
e. the genetic code is ambiguous but not degenerate. - Answers- C
Which of the following is not required for transcription?
a. A DNA template
b. A primer
c. Ribonucleoside triphosphates
d. RNA polymerase
e. All of the above are required for transcription. - Answers- B
In prokaryotes, the region of DNA to which RNA polymerase binds most tightly is the
a. promoter.
b. poly C center.
c. enhancer.
d. operator site.
e. minor groove. - Answers- A
,RNA polymerase is:
a. an RNA-directed DNA polymerase.
b. an RNA-directed RNA polymerase.
c. a form of RNA.
d. a ribozyme.
e. a DNA-directed RNA polymerase. - Answers- E
A codon is _______ nucleotides long, and there are _______ different possible codons
in total.
a. 2; 16
b. 2; 64
c. 3; 16
d. 3; 64
e. 4; 64 - Answers- D
The stop codons code for
a. no amino acid.
b. methionine.
c. glycine.
d. halt enzyme.
e. DNA binding protein. - Answers- A
The amino acids in proteins are encoded by _______ different codons.
a. 20
b. 23
c. 42
d. 61
e. 64 - Answers- D
Which of the following would be an example of an ambiguous genetic code?
a. One with 61 codons for 20 amino acids
b. One in which UUU and UUA both code for phenylalanine
c. One in which CCU could code for either alanine or leucine
d. All of the above
e. None of the above - Answers- C
Humans share the same genetic code with:
a. just other vertebrates.
b. just other multicellular animals.
c. just other multicellular animals and plants.
d. just other eukaryotes.
, e. all known life. - Answers- E
Aside from using T instead of U, the "coding strand" of DNA is _______ to the mRNA.
a. identical in sequence
b. identical in sequence but antiparallel
c. complementary and parallel
d. complementary and antiparallel
e. complementary and in a random order - Answers- A
The adaptor between mRNA and a protein is:
a. tRNA.
b. a promoter.
c. RNA polymerase.
d. DNA polymerase.
e. DNA. - Answers- A
In eukaryotic cells, translation occurs in the _______ and transcription occurs _______.
a. nucleus; in the nucleus
b. nucleus; in the cytoplasm
c. cytoplasm; in the nucleus
d. nucleus; outside of the cell
e. cytoplasm; outside of the cell - Answers- C
One can argue that although the existence of retroviruses represents a complication of
Crick's central dogma, it does not violate its spirit. The replication mechanism of
retroviruses does not contradict the essence of the central dogma because:
a. retroviruses convert DNA information into RNA information.
b. retroviruses convert RNA information into RNA information.
c. even in retroviruses, information in proteins is not converted into DNA information.
d. even in retroviruses, DNA information is not converted into protein information.
e. retroviruses do not use tRNA. - Answers- C
In a nucleic acid hybridization experiment performed to detect exons, the probe
a. single-stranded DNA.
b. double-stranded DNA.
c. triple-stranded DNA.
d. single-stranded RNA.
e. double-stranded RNA. - Answers- D
When eukaryotic DNA is hybridized with mRNA, the hybrid molecules contain loops of
double-stranded DNA, which are
