Virtual Labs

DNA analysis by agarose gel electrophoresis

1. Which of the following method is commonly used for separation of DNA by electrophoresis?

a: Agarose- horizontal Explanation

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b: PAGE- vertical Explanation

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c: Agarose- vertical Explanation

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d: PAGE- horizontal Explanation

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2. What is the criterion for the movement of DNA fragments on agarose gel during gel electrophoresis?

a: The larger the fragment size, the farther it moves Explanation

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b: The smaller the fragment size, the farther it moves Explanation

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c: Positively charged fragments move to farther end Explanation

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d: Negatively charged fragments do not move Explanation

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3. For the preparation of agarose gel in electrophoresis, agarose is dissolved in

a: TAE buffer Explanation

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b: Distilled water Explanation

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c: Oil based emulsion Explanation

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d: Alcohol Explanation

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4. What applications can gel electrophoresis be used for?

a: Parental Testing Explanation

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b: Criminal Investigations Explanation

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c: Comparing relationships of species Explanation

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d: All of the above Explanation

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5. The separated DNA fragments can be visualized after staining with _____, followed by exposure with _____.

a: β-galactosidase, gamma radiation Explanation

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b: Ethidium bromide, UV radiation Explanation

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c: β-galactosidase, UV radiation Explanation

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d: Ethidium bromide, gamma radiation Explanation

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6. The type and density of the gel are important because

a: Some DNA nucleotides may be lost due to chemical reactions with the gel Explanation

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b: They may cause some DNA molecules to replicate Explanation

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c: They influence the rate of migration of the fragments Explanation

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d: Some DNA molecules may sink to the bottom and not migrate Explanation

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7. Identify the correct sequence of events of agarose gel electrophoresis.

a: Gel preparation → casting the gel → forming wells using comb → cooling the gel → removing comb → loading sample in the wells → turning on power → eluting band to get gene of interest Explanation

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b: Gel preparation → casting the gel → cooling the gel → inserting combs into well → removing comb → turning on power → loading sample in the wells → eluting band to get gene of interest Explanation

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c: Gel preparation → casting the gel → cooling the gel → inserting combs into well → removing comb → loading sample in the wells → turning on power → eluting band to get gene of interest Explanation

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d: Gel preparation → casting the gel → cooling the gel → inserting combs into well → loading sample in the wells → removing comb → turning on power → eluting band to get gene of interest Explanation

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8. Why do the fragments of DNA in gel electrophoresis travel away from the negative electrode?

a: DNA is negatively charged so is attracted to the positive end of the unit Explanation

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b: DNA is positively charged so is attracted to the negative end of the unit Explanation

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c: The agarose gel is negatively charged Explanation

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d: The agarose gel is positively charged Explanation

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9. The electrophoresis apparatus consists of:

a: Electrophoresis unit and DNA separator Explanation

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b: Gel, power pack and buffer chamber Explanation

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c: Electrophoresis unit and buffer chamber Explanation

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d: Power pack and Electrophoresis unit Explanation

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10. What is the purpose of loading a DNA ladder in agarose gel electrophoresis?

a: To measure the size of DNA molecules Explanation

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b: To provide a reference for estimating migration distance Explanation

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c: To separate the DNA molecules Explanation

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d: To determine the charge of DNA molecules Explanation

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