Bio 230 Exam 3 Questions and Answers with Verified Solutions | Latest
2026 Update
Q: the initiation of dna replication takes place in two steps
Answer:
s-Cdk triggers s phase
activates helicases
promotes assembly of proteins at replication fork
prevents re-replication by phosphorylating
Q: telomerase
Answer:
RNP protein plus rna complex
use rna as template
polymerize new dna from rna template in the 5 prime to 3 prime direction
Q: spontaneous loss of a purine base (a and g)
Answer:
depurination
,Bio 230 Exam 3 Questions and Answers with Verified Solutions | Latest
2026 Update
Q: spontaneous loss of an amino group
Answer:
deamination
Q: uv induced covalent bondings of thymines creates
Answer:
thymine dimers
Q: basic mechanism of dna repair
Answer:
damage is recognized and removed by nucleases
repair DNA polymerase fill in the gap in the 5 to 3 direction
dna ligase seals nick in backbone
,Bio 230 Exam 3 Questions and Answers with Verified Solutions | Latest
2026 Update
Q: rna polymerase
Answer:
catalyzes phosphodiester bond
unwinds the dna helix
extends transcript one nucleotide at a time
direction 5 to 3 (adds nucleotides)
synthesis without a primer
error rate 1 in 10^4
Q: transcription produces rna that is complementary to one strand of dna because
Answer:
rna
polymerase always moves in 3 to 5 direction
orientation of promoter determines the template
, Bio 230 Exam 3 Questions and Answers with Verified Solutions | Latest
2026 Update
Q: initiation of transcription in bacteria
Answer:
rna polymerase subunit sigma factor binds promoter
rna synthesis initiated
sigma subunit dissociates
chain elongation continues until terminator sequence
rna polymerasase releases from dna and rna transcript
polymerase re associates with sigma factor
Q: eukaryotic gene transcription
Answer:
tfiiD binds to Tata box causing a distortion in the dna
tfiiD enables binding of tfiiB
more TFs and rna polymerase 2 bind
tfiiH uses atp to pull apart dna at the transcription start site
tfiiH also phosphorylates rna polymerase 2
2026 Update
Q: the initiation of dna replication takes place in two steps
Answer:
s-Cdk triggers s phase
activates helicases
promotes assembly of proteins at replication fork
prevents re-replication by phosphorylating
Q: telomerase
Answer:
RNP protein plus rna complex
use rna as template
polymerize new dna from rna template in the 5 prime to 3 prime direction
Q: spontaneous loss of a purine base (a and g)
Answer:
depurination
,Bio 230 Exam 3 Questions and Answers with Verified Solutions | Latest
2026 Update
Q: spontaneous loss of an amino group
Answer:
deamination
Q: uv induced covalent bondings of thymines creates
Answer:
thymine dimers
Q: basic mechanism of dna repair
Answer:
damage is recognized and removed by nucleases
repair DNA polymerase fill in the gap in the 5 to 3 direction
dna ligase seals nick in backbone
,Bio 230 Exam 3 Questions and Answers with Verified Solutions | Latest
2026 Update
Q: rna polymerase
Answer:
catalyzes phosphodiester bond
unwinds the dna helix
extends transcript one nucleotide at a time
direction 5 to 3 (adds nucleotides)
synthesis without a primer
error rate 1 in 10^4
Q: transcription produces rna that is complementary to one strand of dna because
Answer:
rna
polymerase always moves in 3 to 5 direction
orientation of promoter determines the template
, Bio 230 Exam 3 Questions and Answers with Verified Solutions | Latest
2026 Update
Q: initiation of transcription in bacteria
Answer:
rna polymerase subunit sigma factor binds promoter
rna synthesis initiated
sigma subunit dissociates
chain elongation continues until terminator sequence
rna polymerasase releases from dna and rna transcript
polymerase re associates with sigma factor
Q: eukaryotic gene transcription
Answer:
tfiiD binds to Tata box causing a distortion in the dna
tfiiD enables binding of tfiiB
more TFs and rna polymerase 2 bind
tfiiH uses atp to pull apart dna at the transcription start site
tfiiH also phosphorylates rna polymerase 2
