DP Biology (last assessment 2024)

Syllabus sections »

Additional higher level » Topic 7: Nucleic acids

Topic 7: Nucleic acids

Description

Overview of the essential ideas for this topic.

7.1: The structure of DNA is ideally suited to its function.

7.2: Information stored as a code in DNA is copied onto mRNA.

7.3: Information transferred from DNA to mRNA is translated into an amino acid sequence.

Directly related questions

17N.2.HL.TZ0.07b:
Nitrogen is part of many important substances in living organisms.

Distinguish between transcription and translation.
17N.2.HL.TZ0.07b:
Nitrogen is part of many important substances in living organisms.

Distinguish between transcription and translation.
17N.3.HL.TZ0.03a:
The Hershey and Chase experiment supported DNA as the hereditary material. Describe the experiment.
17N.3.HL.TZ0.03a:
The Hershey and Chase experiment supported DNA as the hereditary material. Describe the experiment.
17N.3.HL.TZ0.a:
The Hershey and Chase experiment supported DNA as the hereditary material. Describe the experiment.
17N.1.HL.TZ0.26: Some regions of DNA do not code for the production of proteins. What are these regions of DNA...
17N.1.HL.TZ0.26: Some regions of DNA do not code for the production of proteins. What are these regions of DNA...
17N.2.HL.TZ0.b:
Nitrogen is part of many important substances in living organisms.

Distinguish between transcription and translation.
18M.2.HL.TZ1.4c: Distinguish between the purpose of free and bound ribosomes.
17N.1.HL.TZ0.27:
Which letter (A–D) indicates where a new nucleotide would attach?
17N.1.HL.TZ0.27:
Which letter (A–D) indicates where a new nucleotide would attach?
18M.1.HL.TZ1.27: What does eukaryotic DNA have that is missing from prokaryotic DNA? A. Uracil B. Promoter...
18M.2.HL.TZ1.4c: Distinguish between the purpose of free and bound ribosomes.
18M.1.HL.TZ1.27: What does eukaryotic DNA have that is missing from prokaryotic DNA? A. Uracil B. Promoter...
18M.1.HL.TZ1.28: What are polysomes? A. Strings of amino acids B. Packages of eight histones with DNA C. Many...
18M.1.HL.TZ1.28: What are polysomes? A. Strings of amino acids B. Packages of eight histones with DNA C. Many...
17N.1.HL.TZ0.28: Which cell component synthesizes actin and myosin? A. Free ribosomes B. Rough endoplasmic...
17N.1.HL.TZ0.28: Which cell component synthesizes actin and myosin? A. Free ribosomes B. Rough endoplasmic...
18M.2.HL.TZ1.c: Distinguish between the purpose of free and bound ribosomes.
18M.1.HL.TZ2.10: Gene expression in cells is regulated at various stages. During which stage does splicing of RNA...
18M.2.HL.TZ2.2b.i: State one role of nucleosomes in eukaryotic cells.
18M.1.HL.TZ2.10: Gene expression in cells is regulated at various stages. During which stage does splicing of RNA...
18M.2.HL.TZ2.2b.i: State one role of nucleosomes in eukaryotic cells.
18M.2.HL.TZ2.b.i: State one role of nucleosomes in eukaryotic cells.
18M.1.HL.TZ2.11: How can environmental factors affect the expression of genes? A. By promoting the replication of...
18M.2.HL.TZ2.2b.ii: Outline how Hershey and Chase’s experiment provided evidence for DNA as the genetic material.
18N.1.HL.TZ0.26: Current understanding of DNA is an example of the accumulated discoveries of many scientists....
18M.1.HL.TZ2.11: How can environmental factors affect the expression of genes? A. By promoting the replication of...
18N.1.HL.TZ0.26: Current understanding of DNA is an example of the accumulated discoveries of many scientists....
18M.2.HL.TZ2.2b.ii: Outline how Hershey and Chase’s experiment provided evidence for DNA as the genetic material.
18M.2.HL.TZ2.b.ii: Outline how Hershey and Chase’s experiment provided evidence for DNA as the genetic material.
18M.1.HL.TZ2.12:
In which image are polysomes visible? (The images do not have the same magnification)
18M.1.HL.TZ2.12:
In which image are polysomes visible? (The images do not have the same magnification)
18M.2.HL.TZ2.2b.iii: State one function for a region of DNA that does not code for proteins.
19M.1.HL.TZ1.26: What contribution did the X-ray diffraction conducted by Rosalind Franklin make to our...
18M.2.HL.TZ2.2b.iii: State one function for a region of DNA that does not code for proteins.
18M.2.HL.TZ2.b.iii: State one function for a region of DNA that does not code for proteins.
18M.2.HL.TZ2.2c.i: Outline the role of the A-site of ribosomes in translation.
18M.2.HL.TZ2.2c.i: Outline the role of the A-site of ribosomes in translation.
18M.2.HL.TZ2.c.i: Outline the role of the A-site of ribosomes in translation.
18M.2.HL.TZ2.2c.ii:
Outline the role of tRNA activating enzymes in translation.
18M.2.HL.TZ2.2c.ii:
Outline the role of tRNA activating enzymes in translation.
18M.2.HL.TZ2.c.ii:
Outline the role of tRNA activating enzymes in translation.
18M.2.HL.TZ2.4a: The diagram shows alpha amylase. Explain the secondary structure of this protein molecule.
18M.2.HL.TZ2.4a: The diagram shows alpha amylase. Explain the secondary structure of this protein molecule.
18M.2.HL.TZ2.a: The diagram shows alpha amylase. Explain the secondary structure of this protein molecule.
18N.2.HL.TZ0.2a.i:
Label a peptide bond in the diagram of a polypeptide.
18N.2.HL.TZ0.2a.i:
Label a peptide bond in the diagram of a polypeptide.
18N.2.HL.TZ0.a.i:
Label a peptide bond in the diagram of a polypeptide.
18N.2.HL.TZ0.2a.ii: Outline the primary structure of proteins.
18N.2.HL.TZ0.2a.ii: Outline the primary structure of proteins.
18N.2.HL.TZ0.a.ii: Outline the primary structure of proteins.
18N.2.HL.TZ0.3a: State one similarity and one difference between the structure of genes and short tandem repeats.
18N.2.HL.TZ0.3a: State one similarity and one difference between the structure of genes and short tandem repeats.
18N.2.HL.TZ0.a: State one similarity and one difference between the structure of genes and short tandem repeats.
18N.2.HL.TZ0.3b: Outline the role of short tandem repeats in DNA profiling.
18N.2.HL.TZ0.3b: Outline the role of short tandem repeats in DNA profiling.
18N.2.HL.TZ0.b: Outline the role of short tandem repeats in DNA profiling.
19M.1.HL.TZ1.26: What contribution did the X-ray diffraction conducted by Rosalind Franklin make to our...
19M.1.HL.TZ2.11:
Hershey and Chase used a bacteriophage (a virus that infects bacteria) to investigate the chemical nature of genes. The diagram shows a bacteriophage.

[Source: Graham Knott and Christel Genoud, ‘Commentary: is EM dead?’, Journal of Cell Science (2013),
126: 4545–4552, reproduced with permission. http://jcs.biologists.org/content/126/20/4545.figures-only
doi: 10.1242/jcs.124123 http://www.biologists.com/journal-of-cell-science]

The sulphur in the protein and the phosphorus in the DNA of the bacteriophage were radioactively labelled. The data obtained after bacterial infection and centrifugation are shown in the table.

What did Hershey and Chase conclude from their experiment?

A. DNA was mainly outside the bacterial cells.

B. Viruses infect bacterial cells with proteins.

C. Viral DNA was found within the bacterial cells.

D. Neither protein nor DNA were chemicals making up genes in viruses.
19M.1.HL.TZ1.27:
The diagram shows the arrangement of introns and exons in a segment of pre-mRNA. Pre-mRNA is immature mRNA containing introns and exons.

Which is a mature mRNA molecule derived from the pre-mRNA by splicing?

[Source: © International Baccalaureate Organization 2019]
19M.1.HL.TZ2.11:
Hershey and Chase used a bacteriophage (a virus that infects bacteria) to investigate the chemical nature of genes. The diagram shows a bacteriophage.

[Source: Graham Knott and Christel Genoud, ‘Commentary: is EM dead?’, Journal of Cell Science (2013),
126: 4545–4552, reproduced with permission. http://jcs.biologists.org/content/126/20/4545.figures-only
doi: 10.1242/jcs.124123 http://www.biologists.com/journal-of-cell-science]

The sulphur in the protein and the phosphorus in the DNA of the bacteriophage were radioactively labelled. The data obtained after bacterial infection and centrifugation are shown in the table.

What did Hershey and Chase conclude from their experiment?

A. DNA was mainly outside the bacterial cells.

B. Viruses infect bacterial cells with proteins.

C. Viral DNA was found within the bacterial cells.

D. Neither protein nor DNA were chemicals making up genes in viruses.
19M.1.HL.TZ1.27:
The diagram shows the arrangement of introns and exons in a segment of pre-mRNA. Pre-mRNA is immature mRNA containing introns and exons.

Which is a mature mRNA molecule derived from the pre-mRNA by splicing?

[Source: © International Baccalaureate Organization 2019]
19M.1.HL.TZ2.12: What are the functions of DNA primase and DNA polymerase I in DNA replication?
19M.2.HL.TZ1.7a: Outline the roles of helicase and ligase in DNA replication.
19M.1.HL.TZ1.28:
The image shows a polysome in a bacterial cell.

[Source: © International Baccalaureate Organization 2019]

How many genes have been transcribed?

A. 1

B. 2

C. 3

D. 4
19M.1.HL.TZ2.12: What are the functions of DNA primase and DNA polymerase I in DNA replication?
19M.1.HL.TZ1.28:
The image shows a polysome in a bacterial cell.

[Source: © International Baccalaureate Organization 2019]

How many genes have been transcribed?

A. 1

B. 2

C. 3

D. 4
19M.1.HL.TZ2.13: A nucleotide containing dideoxyribose is shown. What is the reason for the use of...
19M.2.HL.TZ1.7a: Outline the roles of helicase and ligase in DNA replication.
19M.2.HL.TZ1.a: Outline the roles of helicase and ligase in DNA replication.
19N.2.HL.TZ0.6c: Explain how a polypeptide chain is synthesized in a eukaryotic cell.
19M.2.HL.TZ2.2a.iii:
DNA has regions that do not code for proteins. State two functions of these regions.

1.

2.
19M.2.HL.TZ2.2a.iii:
DNA has regions that do not code for proteins. State two functions of these regions.

1.

2.
19M.2.HL.TZ2.a.iii:
DNA has regions that do not code for proteins. State two functions of these regions.

1.

2.
19M.2.HL.TZ2.2b.i: Outline the difference in methylation pattern between tumorous and normal tissue samples.
19M.2.HL.TZ2.2b.i: Outline the difference in methylation pattern between tumorous and normal tissue samples.
19M.2.HL.TZ2.b.i: Outline the difference in methylation pattern between tumorous and normal tissue samples.
19M.2.HL.TZ2.2b.ii: Suggest a way methylation may affect tumour cell genes.
19M.2.HL.TZ2.2b.ii: Suggest a way methylation may affect tumour cell genes.
19M.2.HL.TZ2.b.ii: Suggest a way methylation may affect tumour cell genes.
19M.1.HL.TZ2.13: A nucleotide containing dideoxyribose is shown. What is the reason for the use of...
19M.1.HL.TZ2.14: What applies to DNA base sequences? I. Some genes do not code for proteins. II. Promoters are...
19M.1.HL.TZ2.14: What applies to DNA base sequences? I. Some genes do not code for proteins. II. Promoters are...
19N.1.HL.TZ0.26: What is a function of DNA polymerase I? A. Adds nucleotides in a 5’ to 3’ direction to elongate...
19N.1.HL.TZ0.26: What is a function of DNA polymerase I? A. Adds nucleotides in a 5’ to 3’ direction to elongate...
19N.2.HL.TZ0.6c: Explain how a polypeptide chain is synthesized in a eukaryotic cell.
19N.1.HL.TZ0.27:
In the diagram of a ribosome, which letter indicates the P site?

[Source: iStock.com/ttsz]
19N.1.HL.TZ0.27:
In the diagram of a ribosome, which letter indicates the P site?

[Source: iStock.com/ttsz]
19N.2.HL.TZ0.c: Explain how a polypeptide chain is synthesized in a eukaryotic cell.
20N.2.HL.TZ0.6c:
Explain how polypeptides are produced by the process of translation.
19N.1.HL.TZ0.28: How do R group interactions contribute to protein structure? I. Determining the sequence of...
19N.1.HL.TZ0.28: How do R group interactions contribute to protein structure? I. Determining the sequence of...
20N.1.HL.TZ0.26: The number of protein-coding genes in the human genome is estimated to be about 20 000, which is...
20N.1.HL.TZ0.26: The number of protein-coding genes in the human genome is estimated to be about 20 000, which is...
20N.2.HL.TZ0.6c:
Explain how polypeptides are produced by the process of translation.
20N.1.HL.TZ0.27: Which are two proteins that assist in the unwinding and separation of DNA strands during...
20N.1.HL.TZ0.27: Which are two proteins that assist in the unwinding and separation of DNA strands during...
20N.2.HL.TZ0.c:
Explain how polypeptides are produced by the process of translation.
21M.1.HL.TZ1.26: Which regions of DNA code for the production of specific proteins? A. Telomeres B. Genes for...
20N.1.HL.TZ0.28:
The diagram shows the three-dimensional structure of tRNA.

[Source: Structure reproduced with the kind permission of N.R. Voss.]

What can attach to the region marked X?

A. mRNA

B. An amino acid

C. An anticodon

D. The P site of the ribosome
20N.1.HL.TZ0.28:
The diagram shows the three-dimensional structure of tRNA.

[Source: Structure reproduced with the kind permission of N.R. Voss.]

What can attach to the region marked X?

A. mRNA

B. An amino acid

C. An anticodon

D. The P site of the ribosome
21M.1.HL.TZ1.26: Which regions of DNA code for the production of specific proteins? A. Telomeres B. Genes for...
21M.1.HL.TZ1.27: Which statement applies to tRNA? A. There is at least one type of tRNA that combines with each...
21M.1.HL.TZ1.27: Which statement applies to tRNA? A. There is at least one type of tRNA that combines with each...
21N.1.HL.TZ1.26:
Rosalind Franklin produced X-ray diffraction images of DNA.

[Source: © King’s College, London. KCL Department of Biophysics KDBP/1/1.]

Which previously unknown aspect of DNA was deduced from these images?

A. Chromosomes are made of DNA.

B. Deoxyribose sugar is attached to a phosphate group.

C. The base A pairs with T and C with G.

D. The DNA molecule is a double helix.
21M.1.HL.TZ2.26:
The graph shows results of an experiment by Hershey and Chase in 1952 in which bacteria were infected with a mixture of virus particles labelled with either ³²P or ³⁵S. A suspension of the infected bacteria was agitated with a blender, and samples collected from the suspension were centrifuged to record the percentage of isotope remaining on the outside of the cells.

[Source: Republished with permission of ROCKEFELLER UNIVERSITY PRESS, from Independent functions of protein and nucleic acid in growth of bacteriophage. Hershey, A.D. and Chase, M., 1952. (Journal of General Physiology, 36(1), p.47). Society of General Physiologists, Rockefeller Institute for Medical Research, Rockefeller Institute; permission conveyed through Copyright Clearance Center, Inc.]

What do curves X and Y represent?
21M.1.HL.TZ2.26:
The graph shows results of an experiment by Hershey and Chase in 1952 in which bacteria were infected with a mixture of virus particles labelled with either ³²P or ³⁵S. A suspension of the infected bacteria was agitated with a blender, and samples collected from the suspension were centrifuged to record the percentage of isotope remaining on the outside of the cells.

[Source: Republished with permission of ROCKEFELLER UNIVERSITY PRESS, from Independent functions of protein and nucleic acid in growth of bacteriophage. Hershey, A.D. and Chase, M., 1952. (Journal of General Physiology, 36(1), p.47). Society of General Physiologists, Rockefeller Institute for Medical Research, Rockefeller Institute; permission conveyed through Copyright Clearance Center, Inc.]

What do curves X and Y represent?
21M.1.HL.TZ2.27:
What is a feature of transcription in the single-celled organism shown in the electron micrograph?

[Source: George E. Palade Electron Microscopy Slide Collection Harvey Cushing/John Hay Whitney Medical Library Yale University Library.]

A. mRNA splicing

B. Removal of introns

C. Codon-anticodon binding

D. Synthesis of RNA in a 5′ to 3′ direction
21M.1.HL.TZ2.27:
What is a feature of transcription in the single-celled organism shown in the electron micrograph?

[Source: George E. Palade Electron Microscopy Slide Collection Harvey Cushing/John Hay Whitney Medical Library Yale University Library.]

A. mRNA splicing

B. Removal of introns

C. Codon-anticodon binding

D. Synthesis of RNA in a 5′ to 3′ direction
21M.1.HL.TZ2.28: The mRNA codon UAC codes for the amino acid tyrosine. Which tRNA carries tyrosine?
21M.1.HL.TZ2.28: The mRNA codon UAC codes for the amino acid tyrosine. Which tRNA carries tyrosine?
21N.1.HL.TZ1.26:
Rosalind Franklin produced X-ray diffraction images of DNA.

[Source: © King’s College, London. KCL Department of Biophysics KDBP/1/1.]

Which previously unknown aspect of DNA was deduced from these images?

A. Chromosomes are made of DNA.

B. Deoxyribose sugar is attached to a phosphate group.

C. The base A pairs with T and C with G.

D. The DNA molecule is a double helix.
21N.1.HL.TZ1.27:
What is the difference between the DNA of adult identical (monozygotic) twins?

A. Order of genes

B. Sequence of nucleotides

C. Methylation pattern

D. Ratio of complementary base pairs
21N.2.HL.TZ0.4b:
Describe the secondary structure of proteins.
21N.1.HL.TZ1.27:
What is the difference between the DNA of adult identical (monozygotic) twins?

A. Order of genes

B. Sequence of nucleotides

C. Methylation pattern

D. Ratio of complementary base pairs
21N.2.HL.TZ0.4b:
Describe the secondary structure of proteins.
21N.2.HL.TZ0.b:
Describe the secondary structure of proteins.
21N.1.HL.TZ1.28:
What is the primary function of the free ribosomes shown in the electron micrograph?

[Source: J Gordon Betts, et al. Anatomy and Physiology. Houston Texas: OpenStax, 2013. https://openstax.org/books/
anatomy-and-physiology/pages/3-2-the-cytoplasm-and-cellular-organelles. Image file available at https://commons.
wikimedia.org/wiki/File:0313_Endoplasmic_Reticulum.jpg#/media/File:0313_Endoplasmic_Reticulum_b_labeled.
png. This file is licensed under the Creative Commons Attribution 3.0 Unported license. https://creativecommons.org/
licenses/by/3.0/deed.en.]

A. Synthesize proteins to be used within the cell

B. Synthesize proteins for use in lysosomes

C. Carry amino acids to mRNA for protein synthesis

D. Synthesize proteins for secretion
21N.1.HL.TZ1.28:
What is the primary function of the free ribosomes shown in the electron micrograph?

[Source: J Gordon Betts, et al. Anatomy and Physiology. Houston Texas: OpenStax, 2013. https://openstax.org/books/
anatomy-and-physiology/pages/3-2-the-cytoplasm-and-cellular-organelles. Image file available at https://commons.
wikimedia.org/wiki/File:0313_Endoplasmic_Reticulum.jpg#/media/File:0313_Endoplasmic_Reticulum_b_labeled.
png. This file is licensed under the Creative Commons Attribution 3.0 Unported license. https://creativecommons.org/
licenses/by/3.0/deed.en.]

A. Synthesize proteins to be used within the cell

B. Synthesize proteins for use in lysosomes

C. Carry amino acids to mRNA for protein synthesis

D. Synthesize proteins for secretion
22M.1.HL.TZ1.26: The image shows a replication fork. Which row identifies X, Y and Z in the diagram?
21N.2.HL.TZ0.6a:
Draw labelled diagrams to show the structure of RNA nucleotides and how they are linked together to form a molecule of RNA.
21N.2.HL.TZ0.6a:
Draw labelled diagrams to show the structure of RNA nucleotides and how they are linked together to form a molecule of RNA.
21N.2.HL.TZ0.a:
Draw labelled diagrams to show the structure of RNA nucleotides and how they are linked together to form a molecule of RNA.
22M.1.HL.TZ1.26: The image shows a replication fork. Which row identifies X, Y and Z in the diagram?
21N.2.HL.TZ0.6b:
Explain transcription.
21N.2.HL.TZ0.6b:
Explain transcription.
21N.2.HL.TZ0.b:
Explain transcription.
22M.1.HL.TZ2.26:
The diagram shows the structure of a nucleosome.

[Source: Zephyris. Nucleosome 1KX5 colour coded. Available at https://en.wikipedia.org/wiki/Nucleosome#/media/File:Nucleosome_1KX5_colour_coded.png
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license (https://creativecommons.org/licenses/by-sa/3.0/deed.en).]

What is the structure labelled T?

A. 5' end of RNA

B. 5' end of uncoiled DNA

C. N-terminal tail of one DNA strand

D. N-terminal tail of one histone
22M.1.HL.TZ1.27: During modification in eukaryotes, mRNA is spliced. What is splicing of mRNA? A. Separation of...
22M.1.HL.TZ2.26:
The diagram shows the structure of a nucleosome.

[Source: Zephyris. Nucleosome 1KX5 colour coded. Available at https://en.wikipedia.org/wiki/Nucleosome#/media/File:Nucleosome_1KX5_colour_coded.png
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license (https://creativecommons.org/licenses/by-sa/3.0/deed.en).]

What is the structure labelled T?

A. 5' end of RNA

B. 5' end of uncoiled DNA

C. N-terminal tail of one DNA strand

D. N-terminal tail of one histone
22M.1.HL.TZ1.27: During modification in eukaryotes, mRNA is spliced. What is splicing of mRNA? A. Separation of...
22M.1.HL.TZ2.27: Promoters are non-coding regions in DNA. What is the role of a promoter? A. It starts...
22M.1.HL.TZ1.28:
This DNA sequence was used to synthesize a polypeptide.

DNA (sense strand): 3′ T A C T G A 5′

DNA (template strand): 5′ A T G A C T 3′

Which are the bases of the tRNA (anticodons)?

A. T A C T G A

B. U A C U G A

C. A U G A C U

D. A T G A C T
22M.1.HL.TZ2.27: Promoters are non-coding regions in DNA. What is the role of a promoter? A. It starts...
22M.2.HL.TZ2.5a.i: Describe the structure of nucleosomes.
22M.1.HL.TZ1.28:
This DNA sequence was used to synthesize a polypeptide.

DNA (sense strand): 3′ T A C T G A 5′

DNA (template strand): 5′ A T G A C T 3′

Which are the bases of the tRNA (anticodons)?

A. T A C T G A

B. U A C U G A

C. A U G A C U

D. A T G A C T
22M.1.HL.TZ2.28:
The diagram shows the structure of E. coli ribonuclease HI, a bacterial protein consisting of one polypeptide chain.

[Source: RCSB PDB. 1JL1 D10A E. coli ribonuclease HI. PDB DOI: 10.2210/pdb1JL1/pdb Mol* (Goedken, E.R., Marqusee, S. Native-state energetics of a thermostabilized variant of ribonuclease HI. (2001) J Mol Biol 314:
863–871 DOI:10.1006/jmbi.2001.5184) [image online] Available at: https://www.rcsb.org/structure/1jl1
[Accessed 25 November 2019]. This file is licensed under the Creative Commons CC0 1.0 Universal (https://creativecommons.org/publicdomain/zero/1.0/).]

Which level(s) of protein structure is/are shown?

A. Alpha helix only

B. Quaternary only

C. Primary and secondary

D. Secondary and tertiary
22M.1.HL.TZ2.28:
The diagram shows the structure of E. coli ribonuclease HI, a bacterial protein consisting of one polypeptide chain.

[Source: RCSB PDB. 1JL1 D10A E. coli ribonuclease HI. PDB DOI: 10.2210/pdb1JL1/pdb Mol* (Goedken, E.R., Marqusee, S. Native-state energetics of a thermostabilized variant of ribonuclease HI. (2001) J Mol Biol 314:
863–871 DOI:10.1006/jmbi.2001.5184) [image online] Available at: https://www.rcsb.org/structure/1jl1
[Accessed 25 November 2019]. This file is licensed under the Creative Commons CC0 1.0 Universal (https://creativecommons.org/publicdomain/zero/1.0/).]

Which level(s) of protein structure is/are shown?

A. Alpha helix only

B. Quaternary only

C. Primary and secondary

D. Secondary and tertiary
22N.2.HL.TZ0.4a: Identify the protein labelled in the diagram.
22M.2.HL.TZ2.5a.i: Describe the structure of nucleosomes.
22M.2.HL.TZ2.a.i: Describe the structure of nucleosomes.
22M.2.HL.TZ2.5a.iii:
There are multiple tandem repeats of nucleotide segments of DNA found in the non-coding DNA between genes. Outline how tandem repeats are used for DNA profiling.
22M.2.HL.TZ2.5a.iii:
There are multiple tandem repeats of nucleotide segments of DNA found in the non-coding DNA between genes. Outline how tandem repeats are used for DNA profiling.
22M.2.HL.TZ2.a.iii:
There are multiple tandem repeats of nucleotide segments of DNA found in the non-coding DNA between genes. Outline how tandem repeats are used for DNA profiling.
22N.1.HL.TZ0.26: In transcription, which enzyme has a role similar to that of helicase in replication? A. DNA...
22N.2.HL.TZ0.4a: Identify the protein labelled in the diagram.
22N.1.HL.TZ0.26: In transcription, which enzyme has a role similar to that of helicase in replication? A. DNA...
22N.1.HL.TZ0.27:
The diagram illustrates some of the processes involved in DNA replication.

[Source: Rohrmann, G., 2019. AcMNPV DNA replication. [diagram online] Available at:
https://www.ncbi.nlm.nih.gov/books/NBK543453/figure/ch05.F1/ [Accessed 26 October 2021].]

What is shown in the diagram?

A. DNA polymerase bonding nucleotides in a 3’ to 5’ direction

B. Single-stranded DNA-binding proteins on the old strands

C. Gyrase reforming the double helix

D. DNA ligase joining Okazaki fragments in the leading strand
22N.2.HL.TZ0.a: Identify the protein labelled in the diagram.
22N.2.HL.TZ0.4b:
Outline how nucleosomes affect the transcription of DNA.
22N.1.HL.TZ0.27:
The diagram illustrates some of the processes involved in DNA replication.

[Source: Rohrmann, G., 2019. AcMNPV DNA replication. [diagram online] Available at:
https://www.ncbi.nlm.nih.gov/books/NBK543453/figure/ch05.F1/ [Accessed 26 October 2021].]

What is shown in the diagram?

A. DNA polymerase bonding nucleotides in a 3’ to 5’ direction

B. Single-stranded DNA-binding proteins on the old strands

C. Gyrase reforming the double helix

D. DNA ligase joining Okazaki fragments in the leading strand
22N.2.HL.TZ0.4b:
Outline how nucleosomes affect the transcription of DNA.
22N.1.HL.TZ0.28: The diagram shows a ribosome and associated mRNA Which of these events occurs first in...
22N.2.HL.TZ0.b:
Outline how nucleosomes affect the transcription of DNA.
22N.2.HL.TZ0.4c.i: Identify X, the enzyme which copies a DNA sequence.
22N.1.HL.TZ0.28: The diagram shows a ribosome and associated mRNA Which of these events occurs first in...
22N.2.HL.TZ0.4c.i: Identify X, the enzyme which copies a DNA sequence.
22N.2.HL.TZ0.c.i: Identify X, the enzyme which copies a DNA sequence.
22N.2.HL.TZ0.4c.ii: Identify Y, non-coding DNA at the start of a gene.
22N.2.HL.TZ0.4c.ii: Identify Y, non-coding DNA at the start of a gene.
22N.2.HL.TZ0.c.ii: Identify Y, non-coding DNA at the start of a gene.
22N.2.HL.TZ0.4e:
State one reason that identical twins may show different methylation patterns as they grow older.
22N.2.HL.TZ0.4e:
State one reason that identical twins may show different methylation patterns as they grow older.
22N.2.HL.TZ0.e:
State one reason that identical twins may show different methylation patterns as they grow older.
23M.1.HL.TZ1.13:
Dolly the sheep was the first mammal to be cloned from an adult somatic cell.

_{[Source: Squidonius, Public domain, via Wikimedia Commons.
https://commons.wikimedia.org/wiki/File:Dolly_clone.svg.]}

Which DNA did Dolly inherit?

A. Nuclear and mitochondrial DNA from the surrogate ewe

B. Nuclear and mitochondrial DNA from the Finn-Dorset

C. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the Finn-Dorset

D. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the surrogate ewe
23M.1.SL.TZ1.11:
How do DNA and messenger RNA (mRNA) molecules differ in eukaryotes?

A. mRNA is twice the size of DNA and is formed from four different bases.

B. DNA contains ribose while mRNA contains deoxyribose.

C. mRNA has the same bases as DNA but contains ribose.

D. DNA has two strands while mRNA has only one.
23M.1.SL.TZ1.11:
How do DNA and messenger RNA (mRNA) molecules differ in eukaryotes?

A. mRNA is twice the size of DNA and is formed from four different bases.

B. DNA contains ribose while mRNA contains deoxyribose.

C. mRNA has the same bases as DNA but contains ribose.

D. DNA has two strands while mRNA has only one.
23M.1.SL.TZ1.17:
Dolly the sheep was the first mammal to be cloned from an adult somatic cell.

_{[Source: Squidonius, Public domain, via Wikimedia Commons.
https://commons.wikimedia.org/wiki/File:Dolly_clone.svg.]}

Which DNA did Dolly inherit?

A. Nuclear and mitochondrial DNA from the surrogate ewe

B. Nuclear and mitochondrial DNA from the Finn-Dorset

C. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the Finn-Dorset

D. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the surrogate ewe
23M.1.SL.TZ1.17:
Dolly the sheep was the first mammal to be cloned from an adult somatic cell.

_{[Source: Squidonius, Public domain, via Wikimedia Commons.
https://commons.wikimedia.org/wiki/File:Dolly_clone.svg.]}

Which DNA did Dolly inherit?

A. Nuclear and mitochondrial DNA from the surrogate ewe

B. Nuclear and mitochondrial DNA from the Finn-Dorset

C. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the Finn-Dorset

D. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the surrogate ewe
23M.1.SL.TZ2.8: What is the proteome of an individual? A. The amino acids unique to an individual making up the...
23M.1.SL.TZ2.8: What is the proteome of an individual? A. The amino acids unique to an individual making up the...
23M.1.SL.TZ2.10: What is bonded to phosphates in a strand of RNA? A. Only carbohydrates B. Adenine, guanine,...
23M.1.SL.TZ2.10: What is bonded to phosphates in a strand of RNA? A. Only carbohydrates B. Adenine, guanine,...
23M.1.HL.TZ1.13:
Dolly the sheep was the first mammal to be cloned from an adult somatic cell.

_{[Source: Squidonius, Public domain, via Wikimedia Commons.
https://commons.wikimedia.org/wiki/File:Dolly_clone.svg.]}

Which DNA did Dolly inherit?

A. Nuclear and mitochondrial DNA from the surrogate ewe

B. Nuclear and mitochondrial DNA from the Finn-Dorset

C. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the Finn-Dorset

D. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the surrogate ewe
23M.1.HL.TZ1.25:
The image of the X-ray diffraction of calf thymus DNA was obtained by R. Franklin and R. Gosling in 1953.

^{[Source: Franklin, R.E. and Gosling, R.G., 1953. [image online]}
^{Available at: https://scripts.iucr.org/cgi-bin/paper?a00979.}
^{[Accessed 8 March 2022].]}

What does this image show about the structure of DNA?

A. It is associated with histones.

B. It has a helical shape.

C. It contains deoxyribose.

D. It contains four nitrogenous bases.
23M.1.HL.TZ1.25:
The image of the X-ray diffraction of calf thymus DNA was obtained by R. Franklin and R. Gosling in 1953.

^{[Source: Franklin, R.E. and Gosling, R.G., 1953. [image online]}
^{Available at: https://scripts.iucr.org/cgi-bin/paper?a00979.}
^{[Accessed 8 March 2022].]}

What does this image show about the structure of DNA?

A. It is associated with histones.

B. It has a helical shape.

C. It contains deoxyribose.

D. It contains four nitrogenous bases.

Sub sections and their related questions

7.1 DNA structure and replication

17N.3.HL.TZ0.03a:
The Hershey and Chase experiment supported DNA as the hereditary material. Describe the experiment.
17N.1.HL.TZ0.27:
Which letter (A–D) indicates where a new nucleotide would attach?
18M.1.HL.TZ1.27: What does eukaryotic DNA have that is missing from prokaryotic DNA? A. Uracil B. Promoter...
18M.2.HL.TZ2.2b.i: State one role of nucleosomes in eukaryotic cells.
18M.2.HL.TZ2.2b.ii: Outline how Hershey and Chase’s experiment provided evidence for DNA as the genetic material.
18M.2.HL.TZ2.2b.iii: State one function for a region of DNA that does not code for proteins.
18N.1.HL.TZ0.26: Current understanding of DNA is an example of the accumulated discoveries of many scientists....
18N.2.HL.TZ0.3a: State one similarity and one difference between the structure of genes and short tandem repeats.
18N.2.HL.TZ0.3b: Outline the role of short tandem repeats in DNA profiling.
19M.1.HL.TZ1.26: What contribution did the X-ray diffraction conducted by Rosalind Franklin make to our...
19M.1.HL.TZ1.27:
The diagram shows the arrangement of introns and exons in a segment of pre-mRNA. Pre-mRNA is immature mRNA containing introns and exons.

Which is a mature mRNA molecule derived from the pre-mRNA by splicing?

[Source: © International Baccalaureate Organization 2019]
19M.1.HL.TZ2.11:
Hershey and Chase used a bacteriophage (a virus that infects bacteria) to investigate the chemical nature of genes. The diagram shows a bacteriophage.

[Source: Graham Knott and Christel Genoud, ‘Commentary: is EM dead?’, Journal of Cell Science (2013),
126: 4545–4552, reproduced with permission. http://jcs.biologists.org/content/126/20/4545.figures-only
doi: 10.1242/jcs.124123 http://www.biologists.com/journal-of-cell-science]

The sulphur in the protein and the phosphorus in the DNA of the bacteriophage were radioactively labelled. The data obtained after bacterial infection and centrifugation are shown in the table.

What did Hershey and Chase conclude from their experiment?

A. DNA was mainly outside the bacterial cells.

B. Viruses infect bacterial cells with proteins.

C. Viral DNA was found within the bacterial cells.

D. Neither protein nor DNA were chemicals making up genes in viruses.
19M.1.HL.TZ2.12: What are the functions of DNA primase and DNA polymerase I in DNA replication?
19M.1.HL.TZ2.13: A nucleotide containing dideoxyribose is shown. What is the reason for the use of...
19M.1.HL.TZ2.14: What applies to DNA base sequences? I. Some genes do not code for proteins. II. Promoters are...
19M.2.HL.TZ1.7a: Outline the roles of helicase and ligase in DNA replication.
19M.2.HL.TZ2.2a.iii:
DNA has regions that do not code for proteins. State two functions of these regions.

1.

2.
19N.1.HL.TZ0.26: What is a function of DNA polymerase I? A. Adds nucleotides in a 5’ to 3’ direction to elongate...
20N.1.HL.TZ0.27: Which are two proteins that assist in the unwinding and separation of DNA strands during...
21M.1.HL.TZ1.26: Which regions of DNA code for the production of specific proteins? A. Telomeres B. Genes for...
21M.1.HL.TZ1.27: Which statement applies to tRNA? A. There is at least one type of tRNA that combines with each...
21M.1.HL.TZ2.26:
The graph shows results of an experiment by Hershey and Chase in 1952 in which bacteria were infected with a mixture of virus particles labelled with either ³²P or ³⁵S. A suspension of the infected bacteria was agitated with a blender, and samples collected from the suspension were centrifuged to record the percentage of isotope remaining on the outside of the cells.

[Source: Republished with permission of ROCKEFELLER UNIVERSITY PRESS, from Independent functions of protein and nucleic acid in growth of bacteriophage. Hershey, A.D. and Chase, M., 1952. (Journal of General Physiology, 36(1), p.47). Society of General Physiologists, Rockefeller Institute for Medical Research, Rockefeller Institute; permission conveyed through Copyright Clearance Center, Inc.]

What do curves X and Y represent?
21N.1.HL.TZ1.26:
Rosalind Franklin produced X-ray diffraction images of DNA.

[Source: © King’s College, London. KCL Department of Biophysics KDBP/1/1.]

Which previously unknown aspect of DNA was deduced from these images?

A. Chromosomes are made of DNA.

B. Deoxyribose sugar is attached to a phosphate group.

C. The base A pairs with T and C with G.

D. The DNA molecule is a double helix.
21N.1.HL.TZ1.27:
What is the difference between the DNA of adult identical (monozygotic) twins?

A. Order of genes

B. Sequence of nucleotides

C. Methylation pattern

D. Ratio of complementary base pairs
22M.1.HL.TZ1.26: The image shows a replication fork. Which row identifies X, Y and Z in the diagram?
22M.1.HL.TZ2.26:
The diagram shows the structure of a nucleosome.

[Source: Zephyris. Nucleosome 1KX5 colour coded. Available at https://en.wikipedia.org/wiki/Nucleosome#/media/File:Nucleosome_1KX5_colour_coded.png
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license (https://creativecommons.org/licenses/by-sa/3.0/deed.en).]

What is the structure labelled T?

A. 5' end of RNA

B. 5' end of uncoiled DNA

C. N-terminal tail of one DNA strand

D. N-terminal tail of one histone
22M.2.HL.TZ2.5a.i: Describe the structure of nucleosomes.
22M.2.HL.TZ2.5a.iii:
There are multiple tandem repeats of nucleotide segments of DNA found in the non-coding DNA between genes. Outline how tandem repeats are used for DNA profiling.
22N.2.HL.TZ0.4a: Identify the protein labelled in the diagram.
22N.2.HL.TZ0.4b:
Outline how nucleosomes affect the transcription of DNA.
22N.1.HL.TZ0.27:
The diagram illustrates some of the processes involved in DNA replication.

[Source: Rohrmann, G., 2019. AcMNPV DNA replication. [diagram online] Available at:
https://www.ncbi.nlm.nih.gov/books/NBK543453/figure/ch05.F1/ [Accessed 26 October 2021].]

What is shown in the diagram?

A. DNA polymerase bonding nucleotides in a 3’ to 5’ direction

B. Single-stranded DNA-binding proteins on the old strands

C. Gyrase reforming the double helix

D. DNA ligase joining Okazaki fragments in the leading strand
23M.1.HL.TZ1.13:
Dolly the sheep was the first mammal to be cloned from an adult somatic cell.

_{[Source: Squidonius, Public domain, via Wikimedia Commons.
https://commons.wikimedia.org/wiki/File:Dolly_clone.svg.]}

Which DNA did Dolly inherit?

A. Nuclear and mitochondrial DNA from the surrogate ewe

B. Nuclear and mitochondrial DNA from the Finn-Dorset

C. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the Finn-Dorset

D. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the surrogate ewe
23M.1.HL.TZ1.25:
The image of the X-ray diffraction of calf thymus DNA was obtained by R. Franklin and R. Gosling in 1953.

^{[Source: Franklin, R.E. and Gosling, R.G., 1953. [image online]}
^{Available at: https://scripts.iucr.org/cgi-bin/paper?a00979.}
^{[Accessed 8 March 2022].]}

What does this image show about the structure of DNA?

A. It is associated with histones.

B. It has a helical shape.

C. It contains deoxyribose.

D. It contains four nitrogenous bases.
23M.1.SL.TZ1.17:
Dolly the sheep was the first mammal to be cloned from an adult somatic cell.

_{[Source: Squidonius, Public domain, via Wikimedia Commons.
https://commons.wikimedia.org/wiki/File:Dolly_clone.svg.]}

Which DNA did Dolly inherit?

A. Nuclear and mitochondrial DNA from the surrogate ewe

B. Nuclear and mitochondrial DNA from the Finn-Dorset

C. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the Finn-Dorset

D. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the surrogate ewe
23M.1.SL.TZ2.10: What is bonded to phosphates in a strand of RNA? A. Only carbohydrates B. Adenine, guanine,...
19N.1.HL.TZ0.26: What is a function of DNA polymerase I? A. Adds nucleotides in a 5’ to 3’ direction to elongate...
20N.1.HL.TZ0.27: Which are two proteins that assist in the unwinding and separation of DNA strands during...
21M.1.HL.TZ1.26: Which regions of DNA code for the production of specific proteins? A. Telomeres B. Genes for...
21M.1.HL.TZ1.27: Which statement applies to tRNA? A. There is at least one type of tRNA that combines with each...
21M.1.HL.TZ2.26:
The graph shows results of an experiment by Hershey and Chase in 1952 in which bacteria were infected with a mixture of virus particles labelled with either ³²P or ³⁵S. A suspension of the infected bacteria was agitated with a blender, and samples collected from the suspension were centrifuged to record the percentage of isotope remaining on the outside of the cells.

[Source: Republished with permission of ROCKEFELLER UNIVERSITY PRESS, from Independent functions of protein and nucleic acid in growth of bacteriophage. Hershey, A.D. and Chase, M., 1952. (Journal of General Physiology, 36(1), p.47). Society of General Physiologists, Rockefeller Institute for Medical Research, Rockefeller Institute; permission conveyed through Copyright Clearance Center, Inc.]

What do curves X and Y represent?
21N.1.HL.TZ1.26:
Rosalind Franklin produced X-ray diffraction images of DNA.

[Source: © King’s College, London. KCL Department of Biophysics KDBP/1/1.]

Which previously unknown aspect of DNA was deduced from these images?

A. Chromosomes are made of DNA.

B. Deoxyribose sugar is attached to a phosphate group.

C. The base A pairs with T and C with G.

D. The DNA molecule is a double helix.
21N.1.HL.TZ1.27:
What is the difference between the DNA of adult identical (monozygotic) twins?

A. Order of genes

B. Sequence of nucleotides

C. Methylation pattern

D. Ratio of complementary base pairs
22M.1.HL.TZ1.26: The image shows a replication fork. Which row identifies X, Y and Z in the diagram?
22M.1.HL.TZ2.26:
The diagram shows the structure of a nucleosome.

[Source: Zephyris. Nucleosome 1KX5 colour coded. Available at https://en.wikipedia.org/wiki/Nucleosome#/media/File:Nucleosome_1KX5_colour_coded.png
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license (https://creativecommons.org/licenses/by-sa/3.0/deed.en).]

What is the structure labelled T?

A. 5' end of RNA

B. 5' end of uncoiled DNA

C. N-terminal tail of one DNA strand

D. N-terminal tail of one histone
22M.2.HL.TZ2.5a.i: Describe the structure of nucleosomes.
22M.2.HL.TZ2.5a.iii:
There are multiple tandem repeats of nucleotide segments of DNA found in the non-coding DNA between genes. Outline how tandem repeats are used for DNA profiling.
22M.2.HL.TZ2.a.i: Describe the structure of nucleosomes.
22M.2.HL.TZ2.a.iii:
There are multiple tandem repeats of nucleotide segments of DNA found in the non-coding DNA between genes. Outline how tandem repeats are used for DNA profiling.
22N.2.HL.TZ0.4a: Identify the protein labelled in the diagram.
22N.2.HL.TZ0.4b:
Outline how nucleosomes affect the transcription of DNA.
22N.2.HL.TZ0.a: Identify the protein labelled in the diagram.
22N.2.HL.TZ0.b:
Outline how nucleosomes affect the transcription of DNA.
22N.1.HL.TZ0.27:
The diagram illustrates some of the processes involved in DNA replication.

[Source: Rohrmann, G., 2019. AcMNPV DNA replication. [diagram online] Available at:
https://www.ncbi.nlm.nih.gov/books/NBK543453/figure/ch05.F1/ [Accessed 26 October 2021].]

What is shown in the diagram?

A. DNA polymerase bonding nucleotides in a 3’ to 5’ direction

B. Single-stranded DNA-binding proteins on the old strands

C. Gyrase reforming the double helix

D. DNA ligase joining Okazaki fragments in the leading strand
17N.3.HL.TZ0.03a:
The Hershey and Chase experiment supported DNA as the hereditary material. Describe the experiment.
17N.3.HL.TZ0.a:
The Hershey and Chase experiment supported DNA as the hereditary material. Describe the experiment.
17N.1.HL.TZ0.27:
Which letter (A–D) indicates where a new nucleotide would attach?
18M.1.HL.TZ1.27: What does eukaryotic DNA have that is missing from prokaryotic DNA? A. Uracil B. Promoter...
23M.1.HL.TZ1.13:
Dolly the sheep was the first mammal to be cloned from an adult somatic cell.

_{[Source: Squidonius, Public domain, via Wikimedia Commons.
https://commons.wikimedia.org/wiki/File:Dolly_clone.svg.]}

Which DNA did Dolly inherit?

A. Nuclear and mitochondrial DNA from the surrogate ewe

B. Nuclear and mitochondrial DNA from the Finn-Dorset

C. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the Finn-Dorset

D. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the surrogate ewe
23M.1.HL.TZ1.25:
The image of the X-ray diffraction of calf thymus DNA was obtained by R. Franklin and R. Gosling in 1953.

^{[Source: Franklin, R.E. and Gosling, R.G., 1953. [image online]}
^{Available at: https://scripts.iucr.org/cgi-bin/paper?a00979.}
^{[Accessed 8 March 2022].]}

What does this image show about the structure of DNA?

A. It is associated with histones.

B. It has a helical shape.

C. It contains deoxyribose.

D. It contains four nitrogenous bases.
23M.1.SL.TZ1.17:
Dolly the sheep was the first mammal to be cloned from an adult somatic cell.

_{[Source: Squidonius, Public domain, via Wikimedia Commons.
https://commons.wikimedia.org/wiki/File:Dolly_clone.svg.]}

Which DNA did Dolly inherit?

A. Nuclear and mitochondrial DNA from the surrogate ewe

B. Nuclear and mitochondrial DNA from the Finn-Dorset

C. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the Finn-Dorset

D. Mitochondrial DNA from the Scottish Blackface and nuclear DNA from the surrogate ewe
23M.1.SL.TZ2.10: What is bonded to phosphates in a strand of RNA? A. Only carbohydrates B. Adenine, guanine,...
18M.2.HL.TZ2.2b.i: State one role of nucleosomes in eukaryotic cells.
18M.2.HL.TZ2.2b.ii: Outline how Hershey and Chase’s experiment provided evidence for DNA as the genetic material.
18M.2.HL.TZ2.2b.iii: State one function for a region of DNA that does not code for proteins.
18M.2.HL.TZ2.b.i: State one role of nucleosomes in eukaryotic cells.
18M.2.HL.TZ2.b.ii: Outline how Hershey and Chase’s experiment provided evidence for DNA as the genetic material.
18M.2.HL.TZ2.b.iii: State one function for a region of DNA that does not code for proteins.
18N.1.HL.TZ0.26: Current understanding of DNA is an example of the accumulated discoveries of many scientists....
18N.2.HL.TZ0.3a: State one similarity and one difference between the structure of genes and short tandem repeats.
18N.2.HL.TZ0.3b: Outline the role of short tandem repeats in DNA profiling.
18N.2.HL.TZ0.a: State one similarity and one difference between the structure of genes and short tandem repeats.
18N.2.HL.TZ0.b: Outline the role of short tandem repeats in DNA profiling.
19M.1.HL.TZ1.26: What contribution did the X-ray diffraction conducted by Rosalind Franklin make to our...
19M.1.HL.TZ1.27:
The diagram shows the arrangement of introns and exons in a segment of pre-mRNA. Pre-mRNA is immature mRNA containing introns and exons.

Which is a mature mRNA molecule derived from the pre-mRNA by splicing?

[Source: © International Baccalaureate Organization 2019]
19M.1.HL.TZ2.11:
Hershey and Chase used a bacteriophage (a virus that infects bacteria) to investigate the chemical nature of genes. The diagram shows a bacteriophage.

[Source: Graham Knott and Christel Genoud, ‘Commentary: is EM dead?’, Journal of Cell Science (2013),
126: 4545–4552, reproduced with permission. http://jcs.biologists.org/content/126/20/4545.figures-only
doi: 10.1242/jcs.124123 http://www.biologists.com/journal-of-cell-science]

The sulphur in the protein and the phosphorus in the DNA of the bacteriophage were radioactively labelled. The data obtained after bacterial infection and centrifugation are shown in the table.

What did Hershey and Chase conclude from their experiment?

A. DNA was mainly outside the bacterial cells.

B. Viruses infect bacterial cells with proteins.

C. Viral DNA was found within the bacterial cells.

D. Neither protein nor DNA were chemicals making up genes in viruses.
19M.1.HL.TZ2.12: What are the functions of DNA primase and DNA polymerase I in DNA replication?
19M.1.HL.TZ2.13: A nucleotide containing dideoxyribose is shown. What is the reason for the use of...
19M.1.HL.TZ2.14: What applies to DNA base sequences? I. Some genes do not code for proteins. II. Promoters are...
19M.2.HL.TZ1.7a: Outline the roles of helicase and ligase in DNA replication.
19M.2.HL.TZ1.a: Outline the roles of helicase and ligase in DNA replication.
19M.2.HL.TZ2.2a.iii:
DNA has regions that do not code for proteins. State two functions of these regions.

1.

2.
19M.2.HL.TZ2.a.iii:
DNA has regions that do not code for proteins. State two functions of these regions.

1.

2.

7.2 Transcription and gene expression

17N.2.HL.TZ0.07b:
Nitrogen is part of many important substances in living organisms.

Distinguish between transcription and translation.
17N.1.HL.TZ0.26: Some regions of DNA do not code for the production of proteins. What are these regions of DNA...
18M.1.HL.TZ2.10: Gene expression in cells is regulated at various stages. During which stage does splicing of RNA...
18M.1.HL.TZ2.11: How can environmental factors affect the expression of genes? A. By promoting the replication of...
19M.2.HL.TZ2.2b.i: Outline the difference in methylation pattern between tumorous and normal tissue samples.
19M.2.HL.TZ2.2b.ii: Suggest a way methylation may affect tumour cell genes.
20N.1.HL.TZ0.26: The number of protein-coding genes in the human genome is estimated to be about 20 000, which is...
21M.1.HL.TZ2.27:
What is a feature of transcription in the single-celled organism shown in the electron micrograph?

[Source: George E. Palade Electron Microscopy Slide Collection Harvey Cushing/John Hay Whitney Medical Library Yale University Library.]

A. mRNA splicing

B. Removal of introns

C. Codon-anticodon binding

D. Synthesis of RNA in a 5′ to 3′ direction
21N.2.HL.TZ0.6a:
Draw labelled diagrams to show the structure of RNA nucleotides and how they are linked together to form a molecule of RNA.
21N.2.HL.TZ0.6b:
Explain transcription.
22M.1.HL.TZ1.27: During modification in eukaryotes, mRNA is spliced. What is splicing of mRNA? A. Separation of...
22M.1.HL.TZ2.27: Promoters are non-coding regions in DNA. What is the role of a promoter? A. It starts...
22N.2.HL.TZ0.4c.i: Identify X, the enzyme which copies a DNA sequence.
22N.2.HL.TZ0.4c.ii: Identify Y, non-coding DNA at the start of a gene.
22N.2.HL.TZ0.4e:
State one reason that identical twins may show different methylation patterns as they grow older.
22N.1.HL.TZ0.26: In transcription, which enzyme has a role similar to that of helicase in replication? A. DNA...
23M.1.SL.TZ2.8: What is the proteome of an individual? A. The amino acids unique to an individual making up the...
23M.1.SL.TZ2.10: What is bonded to phosphates in a strand of RNA? A. Only carbohydrates B. Adenine, guanine,...
20N.1.HL.TZ0.26: The number of protein-coding genes in the human genome is estimated to be about 20 000, which is...
21M.1.HL.TZ2.27:
What is a feature of transcription in the single-celled organism shown in the electron micrograph?

[Source: George E. Palade Electron Microscopy Slide Collection Harvey Cushing/John Hay Whitney Medical Library Yale University Library.]

A. mRNA splicing

B. Removal of introns

C. Codon-anticodon binding

D. Synthesis of RNA in a 5′ to 3′ direction
21N.2.HL.TZ0.6a:
Draw labelled diagrams to show the structure of RNA nucleotides and how they are linked together to form a molecule of RNA.
21N.2.HL.TZ0.6b:
Explain transcription.
21N.2.HL.TZ0.a:
Draw labelled diagrams to show the structure of RNA nucleotides and how they are linked together to form a molecule of RNA.
21N.2.HL.TZ0.b:
Explain transcription.
22M.1.HL.TZ1.27: During modification in eukaryotes, mRNA is spliced. What is splicing of mRNA? A. Separation of...
22M.1.HL.TZ2.27: Promoters are non-coding regions in DNA. What is the role of a promoter? A. It starts...
22N.2.HL.TZ0.4c.i: Identify X, the enzyme which copies a DNA sequence.
22N.2.HL.TZ0.4c.ii: Identify Y, non-coding DNA at the start of a gene.
22N.2.HL.TZ0.4e:
State one reason that identical twins may show different methylation patterns as they grow older.
22N.2.HL.TZ0.c.i: Identify X, the enzyme which copies a DNA sequence.
22N.2.HL.TZ0.c.ii: Identify Y, non-coding DNA at the start of a gene.
22N.2.HL.TZ0.e:
State one reason that identical twins may show different methylation patterns as they grow older.
22N.1.HL.TZ0.26: In transcription, which enzyme has a role similar to that of helicase in replication? A. DNA...
17N.2.HL.TZ0.07b:
Nitrogen is part of many important substances in living organisms.

Distinguish between transcription and translation.
17N.2.HL.TZ0.b:
Nitrogen is part of many important substances in living organisms.

Distinguish between transcription and translation.
17N.1.HL.TZ0.26: Some regions of DNA do not code for the production of proteins. What are these regions of DNA...
23M.1.SL.TZ2.8: What is the proteome of an individual? A. The amino acids unique to an individual making up the...
23M.1.SL.TZ2.10: What is bonded to phosphates in a strand of RNA? A. Only carbohydrates B. Adenine, guanine,...
18M.1.HL.TZ2.10: Gene expression in cells is regulated at various stages. During which stage does splicing of RNA...
18M.1.HL.TZ2.11: How can environmental factors affect the expression of genes? A. By promoting the replication of...
19M.2.HL.TZ2.2b.i: Outline the difference in methylation pattern between tumorous and normal tissue samples.
19M.2.HL.TZ2.2b.ii: Suggest a way methylation may affect tumour cell genes.
19M.2.HL.TZ2.b.i: Outline the difference in methylation pattern between tumorous and normal tissue samples.
19M.2.HL.TZ2.b.ii: Suggest a way methylation may affect tumour cell genes.

7.3 Translation

17N.2.HL.TZ0.07b:
Nitrogen is part of many important substances in living organisms.

Distinguish between transcription and translation.
17N.1.HL.TZ0.28: Which cell component synthesizes actin and myosin? A. Free ribosomes B. Rough endoplasmic...
18M.1.HL.TZ1.28: What are polysomes? A. Strings of amino acids B. Packages of eight histones with DNA C. Many...
18M.2.HL.TZ1.4c: Distinguish between the purpose of free and bound ribosomes.
18M.2.HL.TZ2.2c.i: Outline the role of the A-site of ribosomes in translation.
18M.2.HL.TZ2.2c.ii:
Outline the role of tRNA activating enzymes in translation.
18M.2.HL.TZ2.4a: The diagram shows alpha amylase. Explain the secondary structure of this protein molecule.
18M.1.HL.TZ2.12:
In which image are polysomes visible? (The images do not have the same magnification)
18N.2.HL.TZ0.2a.i:
Label a peptide bond in the diagram of a polypeptide.
18N.2.HL.TZ0.2a.ii: Outline the primary structure of proteins.
19M.1.HL.TZ1.28:
The image shows a polysome in a bacterial cell.

[Source: © International Baccalaureate Organization 2019]

How many genes have been transcribed?

A. 1

B. 2

C. 3

D. 4
19N.2.HL.TZ0.6c: Explain how a polypeptide chain is synthesized in a eukaryotic cell.
19N.1.HL.TZ0.27:
In the diagram of a ribosome, which letter indicates the P site?

[Source: iStock.com/ttsz]
19N.1.HL.TZ0.28: How do R group interactions contribute to protein structure? I. Determining the sequence of...
20N.2.HL.TZ0.6c:
Explain how polypeptides are produced by the process of translation.
20N.1.HL.TZ0.28:
The diagram shows the three-dimensional structure of tRNA.

[Source: Structure reproduced with the kind permission of N.R. Voss.]

What can attach to the region marked X?

A. mRNA

B. An amino acid

C. An anticodon

D. The P site of the ribosome
21M.1.HL.TZ2.28: The mRNA codon UAC codes for the amino acid tyrosine. Which tRNA carries tyrosine?
21N.1.HL.TZ1.28:
What is the primary function of the free ribosomes shown in the electron micrograph?

[Source: J Gordon Betts, et al. Anatomy and Physiology. Houston Texas: OpenStax, 2013. https://openstax.org/books/
anatomy-and-physiology/pages/3-2-the-cytoplasm-and-cellular-organelles. Image file available at https://commons.
wikimedia.org/wiki/File:0313_Endoplasmic_Reticulum.jpg#/media/File:0313_Endoplasmic_Reticulum_b_labeled.
png. This file is licensed under the Creative Commons Attribution 3.0 Unported license. https://creativecommons.org/
licenses/by/3.0/deed.en.]

A. Synthesize proteins to be used within the cell

B. Synthesize proteins for use in lysosomes

C. Carry amino acids to mRNA for protein synthesis

D. Synthesize proteins for secretion
21N.2.HL.TZ0.4b:
Describe the secondary structure of proteins.
22M.1.HL.TZ1.28:
This DNA sequence was used to synthesize a polypeptide.

DNA (sense strand): 3′ T A C T G A 5′

DNA (template strand): 5′ A T G A C T 3′

Which are the bases of the tRNA (anticodons)?

A. T A C T G A

B. U A C U G A

C. A U G A C U

D. A T G A C T
22M.1.HL.TZ2.28:
The diagram shows the structure of E. coli ribonuclease HI, a bacterial protein consisting of one polypeptide chain.

[Source: RCSB PDB. 1JL1 D10A E. coli ribonuclease HI. PDB DOI: 10.2210/pdb1JL1/pdb Mol* (Goedken, E.R., Marqusee, S. Native-state energetics of a thermostabilized variant of ribonuclease HI. (2001) J Mol Biol 314:
863–871 DOI:10.1006/jmbi.2001.5184) [image online] Available at: https://www.rcsb.org/structure/1jl1
[Accessed 25 November 2019]. This file is licensed under the Creative Commons CC0 1.0 Universal (https://creativecommons.org/publicdomain/zero/1.0/).]

Which level(s) of protein structure is/are shown?

A. Alpha helix only

B. Quaternary only

C. Primary and secondary

D. Secondary and tertiary
22N.1.HL.TZ0.28: The diagram shows a ribosome and associated mRNA Which of these events occurs first in...
23M.1.SL.TZ2.10: What is bonded to phosphates in a strand of RNA? A. Only carbohydrates B. Adenine, guanine,...
19N.2.HL.TZ0.6c: Explain how a polypeptide chain is synthesized in a eukaryotic cell.
19N.2.HL.TZ0.c: Explain how a polypeptide chain is synthesized in a eukaryotic cell.
19N.1.HL.TZ0.27:
In the diagram of a ribosome, which letter indicates the P site?

[Source: iStock.com/ttsz]
19N.1.HL.TZ0.28: How do R group interactions contribute to protein structure? I. Determining the sequence of...
20N.2.HL.TZ0.6c:
Explain how polypeptides are produced by the process of translation.
20N.2.HL.TZ0.c:
Explain how polypeptides are produced by the process of translation.
20N.1.HL.TZ0.28:
The diagram shows the three-dimensional structure of tRNA.

[Source: Structure reproduced with the kind permission of N.R. Voss.]

What can attach to the region marked X?

A. mRNA

B. An amino acid

C. An anticodon

D. The P site of the ribosome
21M.1.HL.TZ2.28: The mRNA codon UAC codes for the amino acid tyrosine. Which tRNA carries tyrosine?
21N.1.HL.TZ1.28:
What is the primary function of the free ribosomes shown in the electron micrograph?

[Source: J Gordon Betts, et al. Anatomy and Physiology. Houston Texas: OpenStax, 2013. https://openstax.org/books/
anatomy-and-physiology/pages/3-2-the-cytoplasm-and-cellular-organelles. Image file available at https://commons.
wikimedia.org/wiki/File:0313_Endoplasmic_Reticulum.jpg#/media/File:0313_Endoplasmic_Reticulum_b_labeled.
png. This file is licensed under the Creative Commons Attribution 3.0 Unported license. https://creativecommons.org/
licenses/by/3.0/deed.en.]

A. Synthesize proteins to be used within the cell

B. Synthesize proteins for use in lysosomes

C. Carry amino acids to mRNA for protein synthesis

D. Synthesize proteins for secretion
21N.2.HL.TZ0.4b:
Describe the secondary structure of proteins.
21N.2.HL.TZ0.b:
Describe the secondary structure of proteins.
22M.1.HL.TZ1.28:
This DNA sequence was used to synthesize a polypeptide.

DNA (sense strand): 3′ T A C T G A 5′

DNA (template strand): 5′ A T G A C T 3′

Which are the bases of the tRNA (anticodons)?

A. T A C T G A

B. U A C U G A

C. A U G A C U

D. A T G A C T
22M.1.HL.TZ2.28:
The diagram shows the structure of E. coli ribonuclease HI, a bacterial protein consisting of one polypeptide chain.

[Source: RCSB PDB. 1JL1 D10A E. coli ribonuclease HI. PDB DOI: 10.2210/pdb1JL1/pdb Mol* (Goedken, E.R., Marqusee, S. Native-state energetics of a thermostabilized variant of ribonuclease HI. (2001) J Mol Biol 314:
863–871 DOI:10.1006/jmbi.2001.5184) [image online] Available at: https://www.rcsb.org/structure/1jl1
[Accessed 25 November 2019]. This file is licensed under the Creative Commons CC0 1.0 Universal (https://creativecommons.org/publicdomain/zero/1.0/).]

Which level(s) of protein structure is/are shown?

A. Alpha helix only

B. Quaternary only

C. Primary and secondary

D. Secondary and tertiary
22N.1.HL.TZ0.28: The diagram shows a ribosome and associated mRNA Which of these events occurs first in...
17N.2.HL.TZ0.07b:
Nitrogen is part of many important substances in living organisms.

Distinguish between transcription and translation.
17N.2.HL.TZ0.b:
Nitrogen is part of many important substances in living organisms.

Distinguish between transcription and translation.
17N.1.HL.TZ0.28: Which cell component synthesizes actin and myosin? A. Free ribosomes B. Rough endoplasmic...
18M.1.HL.TZ1.28: What are polysomes? A. Strings of amino acids B. Packages of eight histones with DNA C. Many...
23M.1.SL.TZ2.10: What is bonded to phosphates in a strand of RNA? A. Only carbohydrates B. Adenine, guanine,...
18M.2.HL.TZ1.4c: Distinguish between the purpose of free and bound ribosomes.
18M.2.HL.TZ1.c: Distinguish between the purpose of free and bound ribosomes.
18M.2.HL.TZ2.2c.i: Outline the role of the A-site of ribosomes in translation.
18M.2.HL.TZ2.2c.ii:
Outline the role of tRNA activating enzymes in translation.
18M.2.HL.TZ2.c.i: Outline the role of the A-site of ribosomes in translation.
18M.2.HL.TZ2.c.ii:
Outline the role of tRNA activating enzymes in translation.
18M.2.HL.TZ2.4a: The diagram shows alpha amylase. Explain the secondary structure of this protein molecule.
18M.2.HL.TZ2.a: The diagram shows alpha amylase. Explain the secondary structure of this protein molecule.
18M.1.HL.TZ2.12:
In which image are polysomes visible? (The images do not have the same magnification)
18N.2.HL.TZ0.2a.i:
Label a peptide bond in the diagram of a polypeptide.
18N.2.HL.TZ0.2a.ii: Outline the primary structure of proteins.
18N.2.HL.TZ0.a.i:
Label a peptide bond in the diagram of a polypeptide.
18N.2.HL.TZ0.a.ii: Outline the primary structure of proteins.
19M.1.HL.TZ1.28:
The image shows a polysome in a bacterial cell.

[Source: © International Baccalaureate Organization 2019]

How many genes have been transcribed?

A. 1

B. 2

C. 3

D. 4