Q: Which formula is used to calculate the relative centrifugal force (RCF) in centrifugation, where $r$ is the radius in centimeters and $N$ is the speed in revolutions per minute (rpm)?

$RCF = 1.12 \times r \times N^2 \times 10^{-5}$

Question 1

Which separation technique is best suited for isolating molecules based on their size and charge, and is commonly used for analyzing gene expression?

Accepted Answer

Electrophoresis

Question 2

In flow cytometry (FACS), what is the primary purpose of using fluorescently labeled antibodies?

Accepted Answer

To identify and sort cells based on specific surface markers

Question 3

Which equation describes the sedimentation rate of a particle in a centrifuge, where $s$ is the sedimentation coefficient, $m$ is the mass, $v$ is the velocity, $r$ is the radius, and $f$ is the frictional coefficient?

Accepted Answer

$s = \frac{m}{f}$

Question 4

A researcher wants to isolate mitochondria from a cell homogenate. Which centrifugation technique should they use for the most effective separation?

Accepted Answer

Differential centrifugation

Question 5

What is the main advantage of using affinity column chromatography in protein purification?

Accepted Answer

It allows for highly specific binding and isolation of target proteins

Question 6

Which imaging technique provides rapid, high-resolution images of thin cell layers and is especially useful for visualizing cell ultrastructure?

Accepted Answer

Cryo-electron microscopy (Cryo-EM)

Question 7

During SDS-PAGE, proteins are separated primarily based on which property?

Accepted Answer

Their size (molecular weight)

Question 8

Which technique would you use to analyze the cell cycle phases in a population of cells?

Accepted Answer

FACS (flow cytometry)

Question 9

A scientist uses RNA interference (RNAi) in a cell culture experiment. What is the expected outcome?

Accepted Answer

Suppression of specific gene expression

Question 10

Which formula is used to calculate the relative centrifugal force (RCF) in centrifugation, where $r$ is the radius in centimeters and $N$ is the speed in revolutions per minute (rpm)?

Accepted Answer

$RCF = 1.12 	imes r 	imes N^2 	imes 10^{-5}$

Question 11

Which gene editing technique utilizes a guide RNA and Cas9 protein to introduce targeted double-strand breaks in DNA?

Accepted Answer

CRISPR genome editing

Question 12

In gel-filtration chromatography, which type of molecules elute first from the column?

Accepted Answer

Large molecules

Question 13

Which technique is most appropriate for separating organelles from a cell homogenate based on their density?

Accepted Answer

Density gradient centrifugation

Question 14

A researcher wants to study the entire set of proteins expressed in a cell under different conditions. Which field of study is most relevant?

Accepted Answer

Proteomics

Question 15

Which step is essential in Western blotting to ensure specific detection of a target protein?

Accepted Answer

Incubation with a primary antibody

Question 16

In thin-layer chromatography, what determines how far a molecule travels up the plate?

Accepted Answer

Its affinity for the stationary phase

Question 17

Which of the following is a key feature of systems biology?

Accepted Answer

Integration of data from genomics, proteomics, and metabolomics

Question 18

A scientist uses FACS to sort cells expressing a specific surface marker. What is the principle behind the sorting mechanism?

Accepted Answer

Cells are sorted based on their fluorescence intensity

Question 19

Which separation technique would be most effective for purifying a protein that binds specifically to a ligand attached to a column matrix?

Accepted Answer

Affinity column chromatography

Question 20

What is the main function of the Cas9 protein in CRISPR genome editing?

Accepted Answer

To introduce double-strand breaks at specific DNA sequences

Cell Biology Techniques: Imaging, Separation, and Molecular Methods

Study Guide - Practice Questions

Study Guide - Flashcards