| Date | May 2018 | Marks available | 2 | Reference code | 18M.2.HL.TZ1.4 |
| Level | Higher level | Paper | Paper 2 | Time zone | Time zone 1 |
| Command term | Outline | Question number | 4 | Adapted from | N/A |
Question
Sickle cell anemia is due to a single base substitution in DNA. Using the diagram, outline how this translates into the production of an abnormal hemoglobin molecule by completing the spaces labelled I, II and III.
DNA codes for the amino acid sequence of polypeptides. List two other functions of DNA.
Distinguish between the purpose of free and bound ribosomes.
Markscheme
a. I: GUG
AND
II: CAC
b. III: Val/valine
Both required. Do not accept GAG to GTC.
a. promotion/repression/regulation of gene expression
b. introns (have functions in regulation of gene expression)
c. telomeres (form caps at the end of chromosomes)
d. coding for tRNAs/rRNAs
e. allows genes/traits/heritable characteristics to be passed to offspring
free ribosomes produce proteins for use inside the cell/cytoplasm whereas bound ribosomes produce proteins for secretion/for use outside the cell/for use in lysosomes
Examiners report
Syllabus sections
- 22M.2.HL.TZ1.4a: State the level of protein structure at which the polypeptide chains of hemoglobin are combined.
- 18M.1.SL.TZ2.13: What determines the genomic size of a species? A. The total amount of DNA B. The total...
- 22M.1.SL.TZ1.13: The table shows the estimated total number of genes in several organisms. What can be...
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17N.3.HL.TZ0.03b:
Some regions of DNA act as telomeres or produce tRNA. State one other function of DNA sequences that do not code for protein.
- 20N.2.SL.TZ0.4b.i: Define mutation.
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19N.2.SL.TZ0.1d:
State the proportion of the ancestral allele for the gene GS3 in the O. rufipogon-III population.
- 17M.2.SL.TZ2.4a.ii: Identify one type of gene mutation.
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22M.2.HL.TZ1.4c:
Outline the role of tRNA in hemoglobin synthesis.
- 17M.1.SL.TZ2.27: The bacterium Neisseria gonorrhoeae causes infections related to the human reproductive...
- 19N.2.SL.TZ0.1f: State one reason for having a control group.
- 17M.1.SL.TZ1.21: Cladograms can be created by comparing DNA or protein sequences. The cladogram on the left is...
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21M.1.SL.TZ2.13:
The electron micrograph shows a section through a plant cell.
[Source: Photo © E. Newcomb.]
In which structure(s) is the genome of the cell contained?
A. Z only
B. X, Y and Z only
C. W and X only
D. X and Y only
- 19M.2.HL.TZ2.7c: Explain the cause of sickle cell anemia and how this disease affects humans.
- 17M.2.HL.TZ1.1f.ii: Suggest a reason for the greater expression of the gene for the urea transporter after an...
- 18M.1.SL.TZ2.12: Some yeast genes can be replaced by human genes that then continue to produce the same human...
- 17M.2.SL.TZ1.1c: Estimate how much smaller drilled oysters raised in seawater at a high CO2 concentration were...
- 22M.1.SL.TZ2.13: Which statement defines alleles? A. They are the different forms of a gene that have the...
- 17M.2.HL.TZ1.7a: Discuss the role of genes and chromosomes in determining individual and shared character...
- 19M.2.HL.TZ1.2b: Outline the causes of sickle cell anemia.
- 17M.1.SL.TZ2.13: What distinguishes an allele from a gene? A. An allele is made of RNA. B. An allele is...
- 19N.2.SL.TZ0.1e: Distinguish between the proportion of ancestral and derived alleles for all three genes in O....
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19M.1.SL.TZ1.13:
The system of sex determination in chimpanzees (Pan troglodytes) is the same as in other mammals. A chimpanzee has 48 chromosomes in the nuclei of its body cells.
What can be deduced from this information?
A. The sex of the chimpanzee
B. The number of genes in each chromosome
C. Whether non-disjunction has occurred
D. The number of autosomes in a diploid cell
- 19N.1.HL.TZ0.10: Which statements are characteristics of alleles? I. Alleles differ significantly in number...
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19M.1.SL.TZ2.8:
Which statement correctly describes genome and proteome?
A. Only the genome but not the proteome can be analysed using gel electrophoresis.
B. The genome and the proteome are the same in all tissues in an organism.
C. In cells of different tissues, the genome is the same while the proteome varies.
D. Only mutations in the proteome but not in the genome cause any variability.
- 21M.1.HL.TZ2.10: What is a feature of the human genome? A. Plasmids B. Messenger RNA C. Transfer RNA D....
