DNA & Molecular Biology Quiz

17 Questions | Total Attempts: 515

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DNA & Molecular Biology Quiz

A quiz for SBI4U Biology, covering DNA structure, replication, transcription & translation.


Questions and Answers
  • 1. 
    DNA nucleotides have three components. Which one of these is NOT part of a DNA nucleotide?
    • A. 

      Phosphate

    • B. 

      Deoxyribose sugar

    • C. 

      Ribose sugar

    • D. 

      A nitrogenous base

  • 2. 
    When considering DNA replication, the best way to describe it is:
    • A. 

      Semiconservative (half old, half new)

    • B. 

      Conservative (original remains, a new one is formed)

    • C. 

      Semipermeable (letting some molecules through)

  • 3. 
    In DNA replication, the enzyme responsible for untwisting & 'unzipping' the DNA strands is....
    • A. 

      Helicase & gyrase

    • B. 

      Ligase

    • C. 

      DNA Polymerase III

    • D. 

      Primase

    • E. 

      RNAse H (DNA Polymerase I)

  • 4. 
    During DNA Replication, a short segment of RNA must form before DNA synthesis can begin. This is done by which enzyme?
    • A. 

      Helicase & gyrase

    • B. 

      DNA Polymerase III

    • C. 

      Ligase

    • D. 

      RNAse H (DNA Polymerase I)

    • E. 

      Primase

  • 5. 
    Small discontinuous fragments of DNA, called Okazaki Fragments, need to be joined together to form a complete strand. Which enzyme carries out this reaction?
    • A. 

      Helicase & gyrase

    • B. 

      DNA Polymerase III

    • C. 

      Ligase

    • D. 

      RNAse H (DNA Polymerase I)

    • E. 

      Primase

  • 6. 
    A new strand of DNA forms when nucleotides are linked together by phosphodiester bonds. The enzyme that enables this is...
    • A. 

      Helicase & gyrase

    • B. 

      DNA Polymerase III

    • C. 

      Ligase

    • D. 

      RNAse H (DNA Polymerase I)

    • E. 

      Primase

  • 7. 
    During DNA replication, there are two other proteins involved that aren't enzymes. These are the SSB's and the "sliding clamp" protein. What are their jobs?
    • A. 

      To speed up the copying of DNA & make sure it happens correctly

    • B. 

      To prevent annealing (closing) of 'unzipped' DNA + increase processivity

    • C. 

      To ensure that any errors in copying are excised before they become permanent

    • D. 

      To bring the correct nucleotides to their correct complementary partners

  • 8. 
    During DNA Transcription, only one strand is copied. This strand is the 3' -- 5' strand, and is called the _______________ strand.
    • A. 

      Leading

    • B. 

      Lagging

    • C. 

      Template

  • 9. 
    During DNA replication, one strand is copied in a nice, smooth, continuous manner. This strand is called the ______________ strand.
    • A. 

      Leading

    • B. 

      Lagging

    • C. 

      Template

  • 10. 
    During DNA replication, one strand is made discontinously, in short fragments, little by little. This is called the ____________________ strand.
    • A. 

      Leading

    • B. 

      Lagging

    • C. 

      Template

  • 11. 
    During transcription, a segment of DNA coding  AACGGATTATAT  would be transcribed to....
    • A. 

      TTGCCTAATATA

    • B. 

      AACGGATTATAT

    • C. 

      AACGGAUUAUAU

    • D. 

      UUGCCUAAUAUA

  • 12. 
    Although there are only 20 amino acids, there are 64 possible codons in the Genetic Code.  This is because of a property of the code called....
    • A. 

      Redundancy

    • B. 

      Repetitiveness

    • C. 

      Recombination

  • 13. 
    Because the mRNA codon, AUG, stands for an amino acid, it means that technically, every protein begins with which amino acid?
    • A. 

      Isoleucine

    • B. 

      Proline

    • C. 

      Methionine

    • D. 

      Tryptophan

  • 14. 
    A sequence of DNA codes: AAAAAAAAAAAAAAAAAAAAA After transcription and translation, it would yield which of the following?
    • A. 

      Nothing.... that's ridiculous!

    • B. 

      A polypeptide composed of 7 Lysines

    • C. 

      A polypeptid composed of 7 Phenylalanines

  • 15. 
    Where in the cell does transcription of DNA occur?
    • A. 

      The nucleus

    • B. 

      The cytoplasm

    • C. 

      Anywhere there is a ribosome

  • 16. 
    Where in the cell does translation of mRNA happen?
    • A. 

      The nucleus

    • B. 

      The cytoplasm

    • C. 

      Anywhere there is a ribosome

  • 17. 
    If an mRNA has a codon which is CGC, then the tRNA anticodon will be...
    • A. 

      CGC

    • B. 

      GCG

    • C. 

      UAU

    • D. 

      ATA