ETS Major Field Test In Biology
UPDATED Questions and CORRECT
Answers
Photoreactivation repair (nucleotide excision repair) - CORRECT ANSWER✔✔- Pyrimidine
dimers formed in DNA due to UV radiation can be repaired by?
SOS repair
Double strand break repair
Mismatch repair
Photoreactivation repair (nucleotide excision repair)
Base excision repair
Mismatch repair - CORRECT ANSWER✔✔- Which of the following repair mechanisms
uses methyl groups to distinguish between parental and daughter strands?
Answers:
Mismatch repair
Photoreactivation repair (Nucleotide excision repair)
SOS repair
Double strand break repair
Base excision repair
Protein - CORRECT ANSWER✔✔- Which of the following types of molecules is always
found in virions?
Answers:
Protein
RNA
Lipid
DNA
Carbohydrate
,Heterochromatin - CORRECT ANSWER✔✔- A Barr body found within the female
mammalian cell's nucleus is an example of ___
Answers:
Euchromatin
Polytene chromosome
Pseudogenes
Heterochromatin
Cistron
Methylation - CORRECT ANSWER✔✔- In vertebrate genes, transcription regulatory
regions that contain CpG islands are inactivated by which CpG modification?
Answers:
Methylation
Ubiquitination
Acetylation
Phosphorylation
Myristoylation
Whether mutant transcription phenotypes are due to perturbation of TBP function. -
CORRECT ANSWER✔✔- TATA-binding protein (TBP) is a key transcription factor in
eukaryotes. A schematic representation of the 240-amino acid TBP of yeast is shown in Fig. 1
below, with the positions of 2 mutations indicated. The boxed area represents the
evolutionarily conserved C-terminal domain of TBP, and the shaded (dark) regions of this
domain represent two repeated elements involved in DNA binding. One mutation (P65S)
changes proline 65 to serine and the other I143N changes isoleucine 143 to asparagine. Fig. 2
below represents autoradiographs of gels containing RNA transcripts produced in extracts of
wild type or mutant cells. Lanes 1-2 are from wild-type yeast (WT), lanes 3-4 are from the
I143N mutant and lanes 5-6 are from P65S mutant, as indicated. Fig. 2A shows transcripts of
a gene transcribed by RNA polymerase I (Pol I). Fig. 2B shows transcripts of a gene
transcribed by RNA polymerase II (Pol II). Fig. 2C shows transcripts
A novel sigma factor is required for transcription initiation at these genes - CORRECT
ANSWER✔✔- A set of genes from Bacillus subtilis that encode the proteins required for
sporulation have conserved DNA sequences -35 and -10 nucleotides before the site of
,transcript initiation. However, the sequence at -35 is different from that seen in most other
genes from that species. Which of the following best explains this difference?
Answers:
Transcription of these genes is induced by cAMP
Translation of the mRNAs transcribed from these genes requires specific ribosomes that
recognize a modified Shine-Dalgarno sequence
A novel sigma factor is required for transcription initiation at these genes
The -35 sequence is the binding site for a repressor of transcription
The replication of these genes requires a specifically modified DNA polymerase.
SOS repair - CORRECT ANSWER✔✔- Which of the following repair mechanisms is often
mutagenic?
Answers:
Mismatch repair
Photoreactivation repair (Nucleotide excision repair)
Base excision repair
SOS repair
Multiple copies of a single chromosome - CORRECT ANSWER✔✔- The polytene
chromosomes seen in Drosophila are
Answers:
Multiple copies of a single chromosome
Produced by repeated rounds of DNA replication followed by nuclear division
Produced only after the completion of mitosis
Not carrying out transcription
smooth in appearance
A base pair is either inserted or deleted in a gene - CORRECT ANSWER✔✔- A frameshift
mutation is created when
Answers:
A codon's nucleotide sequence changes so that it calls for production of a different amino
acid than the original one
, An initial mutation is reversed by a second mutation
A codon's nucleotide sequence changes so that instead of coding for a given amino acid, it
acts to terminate translation
A base pair is either inserted or deleted in a gene
A codon's nucleotide sequence changes but the amino acid it codes for does not change.
A different polypeptide is produced - CORRECT ANSWER✔✔- Which of the following best
explains how mutations in DNA can result in the expression of a new phenotype?
Answers:
The polarity of tRNA becomes the opposite of that of DNA
A different polypeptide is produced
Eukaryotes and prokaryotes have similar ribosomes
The gene is now read in the 3' to 5' direction
Nucleic acids are methylated
A - CORRECT ANSWER✔✔- Based on the figure shown, the RNA primer can be found at
Answers:
C
D
E
A
B
Most eukaryotic genes have introns that cannot be removed in bacteria. - CORRECT
ANSWER✔✔- In genetic engineering, bacteria are commonly used to produce mammalian
proteins. In these instances the cDNA that codes for the protein is used rather than the
genomic DNA. Which of the following provides the best explanation for doing this?
Answers:
It is easier to clone RNA than DNA
It is not possible to clone the entire coding region of the gene
It is easier to clone cDNA than genomic DNA of comparable size
UPDATED Questions and CORRECT
Answers
Photoreactivation repair (nucleotide excision repair) - CORRECT ANSWER✔✔- Pyrimidine
dimers formed in DNA due to UV radiation can be repaired by?
SOS repair
Double strand break repair
Mismatch repair
Photoreactivation repair (nucleotide excision repair)
Base excision repair
Mismatch repair - CORRECT ANSWER✔✔- Which of the following repair mechanisms
uses methyl groups to distinguish between parental and daughter strands?
Answers:
Mismatch repair
Photoreactivation repair (Nucleotide excision repair)
SOS repair
Double strand break repair
Base excision repair
Protein - CORRECT ANSWER✔✔- Which of the following types of molecules is always
found in virions?
Answers:
Protein
RNA
Lipid
DNA
Carbohydrate
,Heterochromatin - CORRECT ANSWER✔✔- A Barr body found within the female
mammalian cell's nucleus is an example of ___
Answers:
Euchromatin
Polytene chromosome
Pseudogenes
Heterochromatin
Cistron
Methylation - CORRECT ANSWER✔✔- In vertebrate genes, transcription regulatory
regions that contain CpG islands are inactivated by which CpG modification?
Answers:
Methylation
Ubiquitination
Acetylation
Phosphorylation
Myristoylation
Whether mutant transcription phenotypes are due to perturbation of TBP function. -
CORRECT ANSWER✔✔- TATA-binding protein (TBP) is a key transcription factor in
eukaryotes. A schematic representation of the 240-amino acid TBP of yeast is shown in Fig. 1
below, with the positions of 2 mutations indicated. The boxed area represents the
evolutionarily conserved C-terminal domain of TBP, and the shaded (dark) regions of this
domain represent two repeated elements involved in DNA binding. One mutation (P65S)
changes proline 65 to serine and the other I143N changes isoleucine 143 to asparagine. Fig. 2
below represents autoradiographs of gels containing RNA transcripts produced in extracts of
wild type or mutant cells. Lanes 1-2 are from wild-type yeast (WT), lanes 3-4 are from the
I143N mutant and lanes 5-6 are from P65S mutant, as indicated. Fig. 2A shows transcripts of
a gene transcribed by RNA polymerase I (Pol I). Fig. 2B shows transcripts of a gene
transcribed by RNA polymerase II (Pol II). Fig. 2C shows transcripts
A novel sigma factor is required for transcription initiation at these genes - CORRECT
ANSWER✔✔- A set of genes from Bacillus subtilis that encode the proteins required for
sporulation have conserved DNA sequences -35 and -10 nucleotides before the site of
,transcript initiation. However, the sequence at -35 is different from that seen in most other
genes from that species. Which of the following best explains this difference?
Answers:
Transcription of these genes is induced by cAMP
Translation of the mRNAs transcribed from these genes requires specific ribosomes that
recognize a modified Shine-Dalgarno sequence
A novel sigma factor is required for transcription initiation at these genes
The -35 sequence is the binding site for a repressor of transcription
The replication of these genes requires a specifically modified DNA polymerase.
SOS repair - CORRECT ANSWER✔✔- Which of the following repair mechanisms is often
mutagenic?
Answers:
Mismatch repair
Photoreactivation repair (Nucleotide excision repair)
Base excision repair
SOS repair
Multiple copies of a single chromosome - CORRECT ANSWER✔✔- The polytene
chromosomes seen in Drosophila are
Answers:
Multiple copies of a single chromosome
Produced by repeated rounds of DNA replication followed by nuclear division
Produced only after the completion of mitosis
Not carrying out transcription
smooth in appearance
A base pair is either inserted or deleted in a gene - CORRECT ANSWER✔✔- A frameshift
mutation is created when
Answers:
A codon's nucleotide sequence changes so that it calls for production of a different amino
acid than the original one
, An initial mutation is reversed by a second mutation
A codon's nucleotide sequence changes so that instead of coding for a given amino acid, it
acts to terminate translation
A base pair is either inserted or deleted in a gene
A codon's nucleotide sequence changes but the amino acid it codes for does not change.
A different polypeptide is produced - CORRECT ANSWER✔✔- Which of the following best
explains how mutations in DNA can result in the expression of a new phenotype?
Answers:
The polarity of tRNA becomes the opposite of that of DNA
A different polypeptide is produced
Eukaryotes and prokaryotes have similar ribosomes
The gene is now read in the 3' to 5' direction
Nucleic acids are methylated
A - CORRECT ANSWER✔✔- Based on the figure shown, the RNA primer can be found at
Answers:
C
D
E
A
B
Most eukaryotic genes have introns that cannot be removed in bacteria. - CORRECT
ANSWER✔✔- In genetic engineering, bacteria are commonly used to produce mammalian
proteins. In these instances the cDNA that codes for the protein is used rather than the
genomic DNA. Which of the following provides the best explanation for doing this?
Answers:
It is easier to clone RNA than DNA
It is not possible to clone the entire coding region of the gene
It is easier to clone cDNA than genomic DNA of comparable size
