Gel electrophoresis is a technique that can be used to separate DNA fragments in forensic chemistry - VCE - SSCE Chemistry - Question 11 - 2008 - Paper 1
Question 11
Gel electrophoresis is a technique that can be used to separate DNA fragments in forensic chemistry. The gel resulting from such a separation experiment carried out ... show full transcript
Worked Solution & Example Answer:Gel electrophoresis is a technique that can be used to separate DNA fragments in forensic chemistry - VCE - SSCE Chemistry - Question 11 - 2008 - Paper 1
Step 1
Fragment A: Fragment X has a higher molecular mass than fragment Y.
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Answer
This statement implies that fragment X is larger than fragment Y, which would generally mean it moves slower through the gel. This statement does not help in identifying the incorrect statement directly.
Step 2
Fragment B: Fragment Y moves through the gel at a faster rate than fragment X.
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Answer
This statement is likely to be true if fragment Y has a lower molecular mass than fragment X as lighter fragments generally move faster in gel electrophoresis.
Step 3
Fragment C: The negative terminal of the power supply is connected to end A of the gel.
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Answer
In gel electrophoresis, the negatively charged DNA fragments migrate towards the positive terminal. Therefore, this statement is true as end A should be negative so DNA can move toward it.
Step 4
Fragment D: Under the conditions of this experiment, the DNA fragments are positively charged.
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Answer
This statement is incorrect because DNA fragments carry a negative charge due to their phosphate backbone. Thus, they migrate toward the positive end of the gel.
