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Question 1:

What is the purpose of density gradient centrifugation?

A) Separating molecules based on size
B) Separating molecules based on density
C) Separating molecules based on charge
D) Separating molecules based on solubility

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Explanation: The correct answer is B) Separating molecules based on density. The purpose of density gradient centrifugation is to separate molecules or particles based on their density. A density gradient is established, and as the sample is centrifuged, particles migrate to specific positions in the gradient based on their density.

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Question 2:

What is used to create the density gradient in density gradient centrifugation?

A) Solvent
B) Salt solution
C) Sucrose solution
D) Density gradient medium

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Explanation: The correct answer is D) Density gradient medium. The density gradient in density gradient centrifugation is created using a density gradient medium. This medium is a substance with varying densities that form a continuous gradient, allowing particles to separate based on their density as they move through the gradient during centrifugation.

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Question 3:

How are particles separated in density gradient centrifugation?

A) By size
B) By density
C) By charge
D) By solubility

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Explanation: The correct answer is B) By density. In density gradient centrifugation, particles are separated based on their density. As the sample is centrifuged, particles migrate to positions in the density gradient where their density matches the surrounding medium, resulting in distinct bands or fractions.

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Question 4:

Which property of particles determines their position in the density gradient during centrifugation?

A) Size
B) Viscosity
C) Charge
D) Density

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Explanation: The correct answer is D) Density. The density of particles determines their position in the density gradient during centrifugation. Heavier or denser particles migrate towards regions with higher density in the gradient, while lighter particles settle in regions with lower density.

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Question 5:

How is the density gradient usually established in density gradient centrifugation?

A) Layering different density solutions
B) Adding a contrast agent to the sample
C) Applying a magnetic field
D) Adjusting the pH of the sample

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Explanation: The correct answer is A) Layering different density solutions. The density gradient is typically established in density gradient centrifugation by layering different density solutions on top of each other. As the sample is centrifuged, particles move through the gradient and settle at positions that match their own density.