5-Bromouracil (bU) is a synthetic chemical mutagen. It bonds with adenine in place of thymine in DNA. During replication, it then binds with guanine. This will then make a guanine-cytosine pair on one strand of DNA instead of an adenine-thymine pair. --- 2 WORK AREA LINES (style=lined) --- --- 8 WORK AREA LINES (style=lined) ---
BIOLOGY, M5 2023 HSC 25b
Huntington's disease is caused by a misfolded protein 'Huntingtin'. It is caused by excess repeats of the DNA sequence CAG on the coding strand of DNA. The mRNA that is produced has the same sequence as the DNA. Use the codon chart, starting in the centre, to identify the amino acid that is repeated. (1 mark)
BIOLOGY, M5 2023 HSC 7 MC
BIOLOGY, M5 EQ-Bank 12 MC
The table shows the base triplets in mRNA for amino acids.
From the table, the amino acid Tryptophan (Trp) can be coded for by the base triplet `text{UGG}`.
Which base triplet could code for the amino acid Arginine (Arg)?
- `text{AAU}`
- `text{UGC}`
- `text{GCC}`
- `text{CGG}`
BIOLOGY, M5 EQ-Bank 14 MC
Haemophilia A is a blood clotting disorder that arises from a defect in the gene F8 which is carried on the X chromosome. The disorder affects the production of a glycoprotein that is one of many components needed to form the platelets which form blood clots when a bleed occurs. It is typically treated with infusions of FVIII product, an inactive single chain polypeptide of 2332 amino acids, which is manufactured using DNA technology on human endothelial cells.
Why is the inactive FVIII polypeptide chain used in the treatment of Haemophilia A?
- It will prevent bleeds from occurring.
- It can take the place of platelets in clotting blood.
- It can be used to manufacture the glycoprotein that is affected by the defective F8 gene.
- It is used as a gene therapy to help the patient manufacture FVIII in their own endothelial cells.
BIOLOGY, M5 2018 HSC 26b
Antidiuretic hormone (ADH) is a protein produced by cells in the hypothalamus. The AVP gene codes for the production of ADH.
- Outline the steps to show how a mutation in the AVP gene could result in changes in the ADH protein. (3 marks)
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- Identify ONE possible effect of the AVP mutation on kidney function. (1 mark)
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BIOLOGY, M5 2015 HSC 14 MC
The table shows the base triplets in mRNA for amino acids.
From the table, the amino acid Serine (Ser) can be coded for by the base triplet UCG.
Which base triplet could code for the amino acid Tyrosine (Tyr)?
- `text{CCU}`
- `text{CAU}`
- `text{UAA}`
- `text{UAC}`
BIOLOGY, M5 2019 HSC 14 MC
The following DNA base sequence is used to code for a sequence of four amino acids.
`text{CGC ATC ATG CTA}`
Which of the following correctly represents the anticodons on the transfer RNA during synthesis of this string of amino acids?
- `text{GCG UAG UAC GAU}`
- `text{CGC AUC AUG CUA}`
- `text{CGC ATC ATG CTA}`
- `text{GCG TAG TAC GAT}`
BIOLOGY, M5 2022 HSC 31b
Lung cancer can be linked to genetic causes. One of the genes frequently studied in lung cancer tissue is the Epidermal Growth Factor Receptor (EGFR) gene. It codes for EGFR protein, which is composed of one polypeptide chain.
- Construct a flow chart to outline the synthesis of the EGFR protein from the EGFR gene. (4 marks)
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The structure of the EGFR protein includes a receptor and an enzyme component. The function of the protein is to help the cell to regulate cell division.
EGFR mutations are present in about 32% of cases of Non-Small Cell Lung Cancer (the most common type of lung cancer).
- Explain how a mutation in the EGFR gene could result in changes in protein structure and function to increase the risk of lung cancer. (4 marks)
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