Syllabus Edition

First teaching 2014

Last exams 2024

|

DNA Structure & Replication (DP IB Biology: HL)

Exam Questions

3 hours35 questions
11 mark

Which of the following statements correctly describes a nucleosome?

  • A strand of DNA coiled around a central core of eight histone proteins.

  • A strand of DNA wrapped around a central core of four histone proteins.

  • A section of supercoiled DNA.

  • A strand of DNA wrapped around a central core of eight chromatin proteins.

Did this page help you?

21 mark

Which of the following is not a conclusion relating to the structure of DNA drawn by Rosalind Franklin from her X-ray diffraction results?

  • DNA is a double helix.

  • DNA contains a repeating structure.

  • Bases pair up according to the rules of complementary base pairing.

  • The turns of the DNA spiral are approximately 3.5 nm apart.

Did this page help you?

31 mark

Which of the following correctly identifies the role of DNA polymerase in DNA replication?

  • Forms hydrogen bonds between the bases of the new nucleotides and the template strand.

  • Unwinds the DNA double helix at the replication fork.

  • Covalently bonds new DNA nucleotides together.

  • Joins up the Okazaki fragments on the lagging strand.

Did this page help you?

41 mark

To which part of the DNA molecule will new nucleotides be covalently bonded during DNA replication?

7-1_q4

    Did this page help you?

    51 mark

    Which of the statements about non-coding DNA is correct?

    • Non coding sequences code for polypeptides and functional RNA such as tRNA.

    • Non coding sequences do not code for polypeptides but can code for functional RNA such as tRNA.

    • Non-coding DNA is only found in between genes.

    • Telomeres are a type of non-coding DNA that regulate gene expression.

    Did this page help you?

    11 mark

    Which of the following are correct statements about nucleosomes?

    I.

    They contain histone proteins

    II.

    They help supercoil the DNA to form a compact structure

    III.

    They are found in both eukaryotes and prokaryotes

    IV.

    They consist of both DNA and chromatin

    • I only

    • I and II

    • I, II and III

    • I, II and IV

    Did this page help you?

    21 mark

    When DNA polymerase adds a new nucleotide to a growing DNA strand, which part of the last nucleotide does it form a bond with?

    • Nitrogenous base

    • 5’ phosphate group of a pentose sugar

    • 1’ Carbon of a pentose sugar

    • 3’ -OH group of a pentose sugar

    Did this page help you?

    31 mark

    Okazaki fragments are short sections of DNA formed during DNA replication.

     Which of the following statements correctly describes why they form?

    • To help the DNA helix unwind

    • To enable replication of the leading strand

    • To act as a template for DNA polymerase 

    • To enable replication of the lagging strand

    Did this page help you?

    41 mark

    What is the correct sequence of events during DNA replication?

    1. DNA gyrase releases the strain within supercoiled areas of DNA.
    2. Helicase unwinds the DNA double helix.
    3. DNA Primase catalyses the synthesis of a short RNA primer.
    4. DNA polymerase I replaces RNA primers with DNA.
    5. DNA polymerase III adds nucleotides to the template strand.
          
       

      first

      last

      A

      I

      II

      III

      IV

      V

      B

      II

      I

      III

      V

      IV

      C

      I

      II

      V

      III

      IV

      D

      II

      III

      IV

      V

      I

      Did this page help you?

      51 mark

      The majority of the eukaryotic genome contains non-coding regions of DNA.

       Which of the following are functions of non-coding DNA?

      I.

      Code for functional RNA molecules

      II.

      Regulate gene expression

      III.

      Allow alternative proteins to be expressed from a gene

      IV.

      Act as telomeres

      • I and II

      • II and III

      • I, II and III

      • I, II, III and IV

      Did this page help you?

      61 mark

      The shaded boxes in the diagram below (left) indicate Variable Number Tandem Repeats (VNTR) from three different loci that were amplified (via PCR) from DNA found at a crime scene. The diagram on the right shows DNA profiles of fragments amplified from the VNTR regions of four suspects.   q6a_7-1_dna_structure_replication_ib_hl_biology_mcq

      Which of these suspects was most likely at the crime scene?

        Did this page help you?

        71 mark

        The dideoxy chain-termination method of DNA sequencing developed by Fredrick Sanger uses dideoxynucleotides. These modified nucleotides lack a 3’-hydroxyl group.

         Which of the following best describes the effect of lacking a 3’-hydroxyl group.

        • It allows the dideoxynucleotide to be labelled with a radioactive or fluorescent tag

        • It increases the efficiency of the sequencing reactions

        • The dideoxynucleotide cannot form a covalent bond with an incoming nucleotide

        • It prevents a thymine base from being incorporated into the developing DNA strand - which terminates the strand

        Did this page help you?

        81 mark

        In the 1950s, Hershey and Chase demonstrated that DNA, not protein, is a factor of heredity responsible for carrying genetic information from one generation to another. They used viruses that were labelled with either radioactive sulphur (35S) or radioactive phosphorus (32P) to infect bacteria.

        Which of these statements correctly describes the results of their experiment?

        • Only bacteria infected by 32P labelled viruses were shown to be radioactive

        • 32P was only detected in the supernatant

        • Only bacteria infected by 35S labelled viruses were shown to be radioactive

        • 35S was detected in the pellet after centrifugation

        Did this page help you?

        91 mark

        Rosalind Franklin’s X-ray diffraction investigations provided crucial evidence that DNA was a double helix - this was instrumental to Crick and Watson developing their model of the structure of DNA.

        Which statements about the structure of DNA were not answered by Franklin’s work?  

        • The distance between nucleotides

        • The arrangement of the nitrogenous bases

        • The pitch of the helix

        • Phosphates were located on the outside of the molecule

        Did this page help you?

        101 mark

        Molecular visualisation software can be used to look at the three-dimensional structure of complex macromolecules such as the nucleosome.

         Which of the following statements about molecular visualisation software are correct?

        I.

        Can help relate structure to chemical or biological behaviour.

        II.

        Can support the design of pharmaceutically active compounds.

        III.

        Can be used to study the interactions between proteins.

        IV.

        Is primarily used to identify if a DNA sequence encodes for a gene.

        • I and II

        • I, II and III 

        • I and IV

        • I, II, III and IV

        Did this page help you?

        11 mark

        Which of the following shows the appearance of the DNA strands that would result after two rounds of DNA replication? Note that the black strands represent DNA present in the original DNA molecule. The grey strands represent newly-synthesised DNA. 

        diagram-10

          Did this page help you?

          2
          Sme Calculator
          1 mark

          A DNA profile was created for two genes in three individuals (A, B, and C).7-1_q2h

          Which of the following statements, relating to the images provided, are correct?

          I.

          The relationship between DNA fragment length and distance moved through the gel is linear.

          II.

          Fragment length is determined by the number of VNTRs.

          III.

          There is a percentage increase of 50 % between the distance moved by fragment Y and that moved by fragment X.

          IV.
          Individual A is homozygous for both of the genes tested.

          • I, II, and III only.

          • I, II, III, and IV.

          • II and IV only.

          • III and IV only.

          Did this page help you?

          31 mark

          Which row correctly identifies the enzymes in a replication fork?7-1_q3h

            I II III IV V
          A. DNA primase DNA ligase DNA polymerase I Helicase DNA polymerase III
          B DNA polymerase III DNA ligase DNA polymerase I Helicase DNA primase
          C. DNA primase DNA ligase DNA primase DNA polymerase III DNA polymerase I
          D. DNA polymerase I DNA polymerase III DNA ligase DNA gyrase DNA helicase

            Did this page help you?

            41 mark

            Which of the following statements about DNA sequencing are correct?

            I.

            Fragments of different length can be separated using gel electrophoresis.

            II.

            PCR requires the use of primers, deoxyribonucleotides, RNA polymerase, and labelled dideoxyribonucleotides.

            III.

            The terminator nucleotide indicates the base present at each position in the sequence.

            IV.

            Dideoxynucleotides are incorporated at specific points in the DNA sequence.

            • I, II, and II only

            • I and III only.

            • II and III only.

            • III and IV only.

            Did this page help you?

            5
            Sme Calculator
            1 mark

            Hershey and Chase carried out an experiment to determine whether the molecule of heredity was protein or DNA; their results after centrifugation are shown below.

            Note the following:

            • Extracellular material is found in the supernatant.
            • The y-axis shows the percentage of each radioactive element present in the supernatant; the remainder of each element ends up in the pellet.7-1_q5h

            Which of the following can be concluded from the results shown?

            • No viral protein enters the infected bacterial cells.

            • DNA has a greater mass than protein.

            • Around 80 % of the viral DNA enters the infected bacterial cells.

            • Most proteins are separated from the bacterial cells by the blending process.

            Did this page help you?