MCQ Bank
What is the primary function of Type II Topoisomerases in the context of circular chromosomes?
- A) Initiating DNA replication
- B) Decatenating the two circular daughter chromosomes
- C) Synthesizing RNA primers
- D) Repairing DNA damage
What is the primary function of meiosis I?
- A) Reduces chromosome number from diploid to haploid
- B) Repair of DNA damage
- C) Production of identical daughter cells
- D) Replication of DNA
What does RNA polymerase do during the elongation phase, in addition to RNA synthesis?
- A) Initiates transcription
- B) Releases RNA products
- C) Binds to the promoter
- D) Unwinds DNA and re-anneals it
What creates the end replication problem in linear chromosomes?
- A) The inability of telomerase to function at the chromosome ends
- B) The absence of DNA ligase
- C) The requirement for an RNA primer to initiate all new DNA synthesis
- D) The presence of multiple origins of replication
What occurs when RNA polymerase produces a transcript longer than 10 nucleotides?
- A) The enzyme releases short transcripts
- B) The DNA strands separate over 13 base pairs
- C) It escapes the promoter
- D) The transcription bubble forms
Which regions of the σ70 factor recognize the –10 and –35 elements of the promoter?
- A) Regions 2 and 3
- B) Regions 1 and 3
- C) Regions 1 and 4
- D) Regions 2 and 4
In semiconservative replication, what does each daughter duplex contain?
- A) Two parental strands
- B) Fragments of old and new DNA
- C) Two completely new strands
- D) One parental strand and one new strand
What is the initial step in transcription initiation?
- A) Binding of RNA polymerase to the promoter
- B) Addition of ribonucleotides to the RNA chain
- C) Escape of RNA polymerase from the promoter
- D) Formation of the transcription bubble
What is a potential mechanism of DNA replication where new and old DNA coexist in the same strand after replication?
- A) Dispersive replication
- B) Semiconservative replication
- C) Reductive replication
- D) Conservative replication
Why is the activity of Type II Topoisomerases critical to the segregation of large linear chromosomes?
- A) Because the large-sized chromosomes necessitate intricate folding into loops attached to a protein scaffold, leading to linkage issues similar to circular chromosomes
- B) Because they lack DNA polymerase
- C) Because they have more replication origins
- D) Because they have fewer histone proteins
What is the key difference between transcription and DNA replication?
- A) Transcription copies the entire genome
- B) RNA polymerase requires a primer
- C) Replication makes many copies of the genome
- D) Transcription involves ribonucleotides
Why do organisms with linear chromosomes need novel strategies for replicating their chromosome ends?
- A) Because they have fewer replication origins
- B) Because they lack DNA repair mechanisms
- C) Because they have more complex DNA sequences
- D) Because the replication fork machinery cannot complete replication of the very ends of linear chromosomes
Which feature of meiosis promotes genetic diversity among the products?
- A) Conservative replication
- B) DNA replication
- C) Formation of a karyotype
- D) Crossing over during meiosis I
Which enzyme is responsible for decatenating the linked daughter DNA molecules after the replication of a circular chromosome?
- A) DNA Polymerase III
- B) Type II Topoisomerases
- C) Helicase
- D) DNA Ligase
How does telomerase solve the end replication problem?
- A) By synthesizing RNA primers
- B) By elongating the 3’ end of the telomeric ssDNA sequences using its own RNA as a template
- C) By removing the RNA primers from the lagging strand
- D) By elongating the 5' end of the DNA
What is the general shape of RNA polymerase enzymes, as described in the text?
- A) Ring
- B) Crab claw
- C) Spiral
- D) Hand
What is the function of the σ factor in bacterial RNA polymerase?
- A) It synthesizes RNA
- B) It binds to the promoter directly
- C) It converts the core enzyme into the RNA polymerase holoenzyme
- D) It initiates transcription at any point on the DNA
According to the Watson-Crick model, what type of DNA replication occurs?
- A) Dispersive replication
- B) Semiconservative replication
- C) Random replication
- D) Conservative replication
Which of the following is NOT a characteristic of transcription?
- A) Less accurate than replication
- B) Involves RNA polymerase
- C) Involves ribonucleotides
- D) Needs a primer
What happens during the termination phase of transcription?
- A) Elongation continues
- B) RNA polymerase releases the RNA product
- C) The RNA polymerase synthesizes more ribonucleotides
- D) DNA strands separate