THE MOLECULAR BASIS OF INHERITANCE
DNA MAKES RNA MAKES PROTEIN
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The longest pieces of DNA will move the least distance.
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The longest pieces of DNA will move the greatest distance.
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The shortest pieces of DNA line up along the middle.
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The shortest pieces of DNA line up an equal distance from the middle
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Detailed explanation-1: -DNA is negatively charged, therefore, when an electric current is applied to the gel, DNA will migrate towards the positively charged electrode. Shorter strands of DNA move more quickly through the gel than longer strands resulting in the fragments being arranged in order of size.
Detailed explanation-2: -To separate DNA using agarose gel electrophoresis, the DNA is loaded into pre-cast wells in the gel and a current applied. The phosphate backbone of the DNA (and RNA) molecule is negatively charged, therefore when placed in an electric field, DNA fragments will migrate to the positively charged anode.
Detailed explanation-3: -Gel electrophoresis is used to separate macromolecules like DNA, RNA and proteins. DNA fragments are separated according to their size. Proteins can be separated according to their size and their charge (different proteins have different charges).
Detailed explanation-4: -Agarose gel electrophoresis is used to resolve DNA fragments on the basis of their molecular weight. Smaller fragments migrate faster than larger ones; the distance migrated on the gel varies inversely with the logarithm of the molecular weight.
Detailed explanation-5: -What is the relationship between DNA fragment size and rate of travel through the agarose gel? The rate of travel is inversely proportional to DNA fragment size. The smaller the DNA fragment, the faster it travels.