ETS major field test in biology Questions with
Answers
1. 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: Photoreactivation repair
(nucleotide excision repair)
2. 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: Mismatch
repair
3. Which of the following types of molecules is always found
in virions? Answers:
Protein
RNA
Lipid
DNA
Carbohydrate: Protein
4. A Barr body found within the female mammalian cell's nucleus
is an example of
Answers:
Euchromatin
,Polytene
chromosome
Pseudogenes
Heterochromatin
Cistron:
Heterochromatin
,5. In vertebrate genes, transcription regulatory regions that contain
CpG islands are inactivated by which CpG modification?
Answers:
Methylation
Ubiquitination
Acetylation
Phosphorylation
Myristoylation:
Methylation
6. 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 mu- tant 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 of a gene transcribed by RNA polymerase III (Pol III).
Lanes 1, 3 and 5 show transcripts produced at 24°C, and lanes 2, 4,
and 6 show transcripts produced at 37°C. Shading of the bands
represents signals of different intensity.
As a control, wild-type TBP was added to mutant extracts prior to
transcription analysis. It was observed that wild-type TBP could
restore transcription by all three RNA polymerases in mutant
, extracts. The controls were performed in order to check
Answers:
Whether mutant transcription phenotypes are temperature sensitive.
Answers
1. 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: Photoreactivation repair
(nucleotide excision repair)
2. 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: Mismatch
repair
3. Which of the following types of molecules is always found
in virions? Answers:
Protein
RNA
Lipid
DNA
Carbohydrate: Protein
4. A Barr body found within the female mammalian cell's nucleus
is an example of
Answers:
Euchromatin
,Polytene
chromosome
Pseudogenes
Heterochromatin
Cistron:
Heterochromatin
,5. In vertebrate genes, transcription regulatory regions that contain
CpG islands are inactivated by which CpG modification?
Answers:
Methylation
Ubiquitination
Acetylation
Phosphorylation
Myristoylation:
Methylation
6. 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 mu- tant 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 of a gene transcribed by RNA polymerase III (Pol III).
Lanes 1, 3 and 5 show transcripts produced at 24°C, and lanes 2, 4,
and 6 show transcripts produced at 37°C. Shading of the bands
represents signals of different intensity.
As a control, wild-type TBP was added to mutant extracts prior to
transcription analysis. It was observed that wild-type TBP could
restore transcription by all three RNA polymerases in mutant
, extracts. The controls were performed in order to check
Answers:
Whether mutant transcription phenotypes are temperature sensitive.
