Use the following information to answer Questions 25–27 - VCE - SSCE Biology - Question 25 - 2015 - Paper 1
Question 25
Use the following information to answer Questions 25–27.
To clone a gene of interest, the following four steps are performed:
A plasmid is cut with a specific rest... show full transcript
Worked Solution & Example Answer:Use the following information to answer Questions 25–27 - VCE - SSCE Biology - Question 25 - 2015 - Paper 1
Step 1
A plasmid is cut with a specific restriction enzyme.
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The plasmid must be cut using a specific restriction enzyme that recognizes a unique sequence within the plasmid DNA. This creates sticky or blunt ends, enabling the insertion of the gene of interest.
Step 2
The gene of interest is ligated into the plasmid.
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After cutting the plasmid, the gene of interest is inserted into the plasmid using a ligase enzyme. This enzyme facilitates the formation of phosphodiester bonds between the plasmid and the gene, completing the cloning process.
Step 3
Plasmids are transferred to bacteria.
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The recombinant plasmids are introduced into competent bacterial cells through a process known as transformation. This process allows the bacteria to take up the plasmid containing the cloned gene.
Step 4
Bacteria are grown on four nutrient agar plates (labelled W, X, Y and Z) that are coated with or without ampicillin and arabinose.
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The transformed bacteria are plated on agar plates containing selective antibiotics (like ampicillin) and, in some cases, arabinose as an inducer for gene expression. This selection method ensures that only those bacteria that have successfully taken up the plasmid will grow.
