W1-W6 MCQ

• Where are proteins made in the cell?

  1. Cytoplasm
  2. Golgi
  3. Lysosomes
  4. Mitochondria
  5. Nucleus
  6. Peroxisomes
  7. Rough endoplasmic reticulum
  8. Smooth endoplasmic reticulum
  9. Trans Golgi network

  1, 4, 7
• A core nucleosome is composed of (choose the best answer):

  1. None of the above
  2. four copies each of histone H2A, H2B, H3 and H4 and 146 bp of DNA
  3. four copies each of histone H2A, H2B, H3 and H4 and 1470 bp of DNA
  4. two copies each of histone H2A, H2B, H3 and H4 and 146 bp of DNA
  5. two copies each of histone H2A, H2B, H3 and H4 and 1460 bp of DNA

  4
• The association of DNA and histone is mainly mediated by?

  1. a combination of hydrogen bonds and covalent bonds
  2. covalent bonds
  3. hydrogen bonds
  4. hydrophobic interactions
  5. van der Waals interactions

  3
• The three major forms of the DNA double helix are A, B and Z form. Which is considered the normal form in the cell?

  B
• If 30% of the bases in a given DNA molecule are adenine. What is the correct percentage of guanine bases in the DNA molecule?

  1. 10%
  2. 20%
  3. 30%
  4. 40%

  2
• Which of the following are examples of how mutations in DNA can occur:

  1. Deletions (loss of nucleotide(s))
  2. Insertions (gain of nucleotide(s))
  3. Purine to purine - e.g. A to G
  4. Pyrimidine to pyrimidine - e.g. C to T
  5. Transversions - Purine to pyrimidine
  6. Transversions - Pyrimidine to purine

  All of the above
• In DNA recombination, which of the following are true:

  1. 2 strands of DNA are involved (one double strand)
  2. 4 strands of DNA are involved (2x double strands)
  3. Genetic exchange (%cross-over) takes place between a pair of homologous DNA sequences
  4. Heteroduplex regions (areas of mismatch) formed
  5. Heteroduplex regions (areas of mismatch) not formed
  6. Heteroduplex regions not repaired by mismatch repair.
  7. Heteroduplex regions repaired by mismatch repair.
  8. Horizontal cleavage of the junction will not produce recombinants.
  9. Horizontal cleavage of the junction will produce recombinants.

  2, 3, 4, 7, 8
• Which of the following are DNA repair mechanisms?

  1. Base Excision Repair (BER)
  2. Base Insertion Repair (BIR)
  3. Direct repair
  4. Homologous recombination repair (HR)
  5. Match Repair (MR)
  6. Mismatch Repair (MMR)
  7. Non-homologous end joining (NHEJ)
  8. Nucleotide Excision Repair (NER)
  9. Nucleotide Insertion Repair (NIR)
  10. Proofreading activity of DNA polymerase

  1, 3, 4, 6, 7, 8, 10
• Why is an RNA primer necessary for DNA replication?

  1. DNA polymerase can only add nucleotides to RNA molecules
  2. DNA polymerase can only add nucleotides to an existing strand
  3. The RNA primer creates the 5' and 3' ends of the strand
  4. The RNA primer is necessary for the activity of DNA ligase

  2
• Because DNA polymerase III can only act from 5' to 3', continuous strand growth can be achieved only along one of the template strands (leading strand), and strand growth along the other strand must occur discontinuously resulting in the production of a series of short sections of new DNA. What are these sections called?

  1. Klenow fragments
  2. None of the above
  3. Okazaki fragments
  4. Replicon fragments

  3
• Transcription is the production of...

  1. DNA from RNA
  2. DNA from protein
  3. RNA from DNA
  4. RNA from protein
  5. protein from DNA
  6. protein from RNA

  3
• Which of the following is true about RNA?

  1. RNA made up of 4 nucleobases thymine (T), adenine (A), cytosine (C), and guanine (G).
  2. RNA made up of 4 nucleobases thymine (T), alanine (A), cytosine (C), and guanine (G).
  3. RNA made up of 4 nucleobases uracil (U), adenine (A), cysteine (C), and guanine (G).
  4. RNA made up of 4 nucleobases uracil (U), adenine (A), cytosine (C), and guanine (G).
  5. RNA made up of 4 nucleobases uracil (U), alanine (A), cytosine (C), and guanine (G).
  6. RNA made up of 4 nucleobases thymine (T), adenine (A), cysteine (C), and guanine (G).

  4
• How many reading frames does a molecule of DNA have?

  6
• Assuming that you start with a methionine, what would be the peptide sequence for the following piece of DNA? AAATGCCTCATAC

  1. ASY
  2. HPM
  3. KCLI
  4. LCLI
  5. MPH
  6. NASY
  7. None of the above

  5
• Which of the following completes this sentence? Cutting the plasmid, and the DNA to be inserted, with two different restriction enzymes is better than cutting with one because cutting with two helps to...

  1. get the correct orientation of the insert in the plasmid.
  2. prevent the insert from being incorrectly orientated, but has no impact on the ligation of the plasmid with itself.
  3. prevent the plasmid from re-ligating on itself.
  4. the plasmid from re-ligating on itself, it does not prevent the insert from being inserted in the incorrect orientation.

  1 and 3
• The purpose of PCR is to:

  1. rapidly amplify DNA at a linear rate
  2. rapidly amplify DNA at a logarithmic rate
  3. rapidly amplify DNA at an exponential rate
  4. rapidly amplify RNA at a linear rate
  5. rapidly amplify RNA at a logarithmic rate
  6. rapidly amplify RNA at an exponential rate

  3
• Put the following points of regulation in order:

  • Protein activation
  • Transcription control
  • RNA processing
  • Transport and localisation
  • RNA degradation
  • Translational control

  Transcriptional control - RNA processing - Transport and localisation - translation control - RNA degradation - protein activation
• Transcriptional control can be exerted by...

  1. Alternative promoters
  2. Inducible transcription factors
  3. Inducible translation factors
  4. Non-Inducible transcription factors
  5. Non-Inducible translation factors
  6. Non-specific transcription factors
  7. Tissue specific transcription factors
  8. Tissue specific translation factors

  1, 2, 7
• Which of the following will contribute to the melting temperature of DNA?

  1. chemical environment - chemical denaturants decrease temp
  2. chemical environment - chemical denaturants increase temp
  3. composition of strand - more A-T = lower temp
  4. composition of strand - more A-T = higher temp
  5. composition of strand - more G-C = higher temp
  6. composition of strand - more G-C = lower temp
  7. length of DNA strand - longer strand = higher temp
  8. length of DNA strand - longer strand = lower temp
  9. length of DNA strand - shorter strand = higher temp
  10. length of DNA strand - shorter strand = lower temp

  1, 3, 5, 7, 10
• Which of the following are true when comparing Northern and Southern blotting?

  1. Northern and Southern blotting both have DNA on the filter membrane.
  2. Northern and Southern blotting both have RNA on the filter membrane.
  3. Northern and Southern blotting can only use fluorescent probes.
  4. Northern blotting has DNA on the filter membrane; Southern blotting has RNA.
  5. Northern blotting has RNA on the filter membrane, Southern blotting has DNA.
  6. The probes used in Northern and Southern blotting can be fluorescent or radio-labelled.

  5 and 6
• Microarrays look for...

  1. Changes in the DNA levels
  2. Changes in the mRNA levels
  3. Changes in the protein levels
  4. Changes in the rRNA levels
  5. Changes in the tRNA levels
  6. Changes in the transcriptome

  2 and 6