Deck 4: Culturing and Visualizing Cells

Question 1

Epithelial cells have distinct surfaces.Which of these surfaces tends to be involved in secreting proteins out of the cell and into the bloodstream?

A)apical
B)basal
C)lateral
D)all of the above

Answer 1

A

Question 2

How does the wavelength of the light used to illuminate a specimen affect the ability to resolve objects within the specimen?

Answer 2

Because the limit of resolution is given by D = (0.61/(N sin α),shorter wavelength light (e.g. ,blue)will provide better resolution than longer wavelength light (e.g. ,red).

Question 3

The fluorescent properties of dyes such as SNARF-1 can provide information on the:

A)location of specific proteins.
B)concentration of H⁺ ions in specific regions of the cell.
C)the amount of RNA in a cell.
D)volume of a cell.

Answer 3

B

Question 4

Which one of the following is the best technique/approach to allow you to localize catalase in peroxisomes?

A)a catalase monoclonal antibody and transmission electron microscopy
B)platinum or gold and scanning electron microscopy
C)FRAP and FRET
D)all of the above

Question 5

In your cell biology laboratory class,you are given a sample of blood.Which of the following results are NOT possible from your analysis of this blood using flow cytometry?

A)isolation of the largest and most dense cells from the smaller blood cells
B)measurement of the amount of DNA in white blood cells
C)relative quantitation of the sizes and shapes of the cells in the blood sample
D)after the addition of fluorescent antibodies specific to T cells,the analysis of T cell abundance and size relative to other cells in the sample

Question 6

Characteristics of transformed cells can include all of the following EXCEPT:

A)aneuploidy.
B)ability to differentiate into different cell types.
C)tight junctions.
D)presence of integrated viral genes.

Question 7

When studying a new protein,it is useful to generate an antibody against it to tag it in experiments designed to study its function and localization.Which of the following is NOT a step needed to generate this new antibody?

A)Mouse spleen cells are fused with myeloma cells.
B)Cells are selected for their ability to divide and grow in the absence of purines in the medium.
C)Mice are injected with the antibody that will tag the new protein.
D)The spleen is isolated from a laboratory mouse.

Question 8

Which of the following could be used to visualize subcellular structure in living cells?

A)transmission electron microscopy
B)scanning electron microscopy
C)bright-field microscopy
D)differential interference light microscopy

Question 9

Separation of most blood cells is difficult,if not impossible,to achieve because they have similar properties and/or densities.What procedure is used to separate T-cells of the immune system from the many other different types of white blood cells or spleen cells? What feature of the T-cell facilitates the isolation protocol?

Question 10

Drugs used to inhibit which molecules would reduce the amount of antibody produced by hybridomas?

A)proteasome inhibitors
B)protease inhibitors
C)transcription inhibitors
D)antibiotics

Question 11

Fixatives such as formaldehyde are routinely used in certain types of electron microscopy and light microscopy.However,fixatives may introduce complications in the analysis of the resulting images.What problems may result from using fixatives?

Question 12

The phenomenon in which a chemical absorbs light at one wavelength and emits it at a specific and longer wavelength is called:

A)differential interference contrast.
B)fluorescence.
C)deconvolution.
D)shadowing.

Question 13

The purpose of treating tissue from an embryonic chick with trypsin and EDTA when generating a primary cell culture is to:

A)break down proteins present in the serum so the cells can use the amino acids for energy.
B)cleave any cell surface proteins so you can grow the chick cells as a suspension culture for

Question 14

What factors necessary for growth of animal cells in culture are provided by serum?

A)amino acids
B)precursors of DNA synthesis
C)growth factors
D)vitamins

Question 15

To visualize cells by immunofluorescence microscopy,the cells must be:

A)placed in a vacuum.
B)living.
C)sectioned.
D)permeabilized.

Question 16

Why are cells cultured in the lab such a useful model system for studying human disease?

A)Cells only function when they are not organized into tissues.
B)Humans are a varied population and extrapolating from physiological studies yields mixed results.
C)Cells cultured in the lab behave exactly the same as cells in the human body.
D)Cells are very inexpensive to grow.

Question 17

All of the following are produced by animal cells in culture and help the cells adhere to the culture dish except:

A)glycoproteins.
B)collagen.
C)phospholipase A.
D)hyaluronic acid.

Question 18

Primary cultures contain _____ (this cell type)which quickly predominate over the other cell types.Given the proper space and nutrients needed to grow,these cells can divide about 50 times,such that after 50 doublings,an original culture of 100 cells would become _____ cells.

A)fibroblasts;2500
B)fibroblasts;1.1 × 10¹⁷
C)epithelial cells;2500
D)epithelial cells;4.5 × 10¹⁵

Question 19

A myeloma cell is best described as:

A)a precursor cell that gives rise to gametes.
B)an immortal immune cell that cannot produce HYPERLINK "http://www.multiplemyeloma.org/about_myeloma/2.10.02.html" \l "immunoglobulin" antibodies.
C)a self-renewing stem cell.
D)The first and third answers are correct.

Question 20

Which of the following allows one to circumvent the theoretical resolution of the microscope?

A)total internal reflection fluorescence microcopy
B)photo-activated localization microscopy
C)indirect immunofluorescence microscopy
D)double-label fluorescence microscopy

Question 21

The best 3-D images of cellular organelles come from:

A)cryoelectron microscopy.
B)immunoelectron microscopy.
C)thin-section electron microscopy.
D)low-angle rotary shadowing with TEM.

Question 22

You are studying lamins and use an antibody method to follow their expression and subcellular localization at the electron microscope level.What process would you use to find these proteins in the bacteria E.coli?

Question 23

Ultracentrifuges allow cell biologists to isolate mitochondria from lysosomes based on organelle differences in:

A)isoelectric point.
B)ionic composition.
C)equilibrium density.
D)size.

Question 24

Rank the following organelles in terms of most dense to least dense:
I)mitochondria II.peroxisomes III.lysosomes

A)I,II,III
B)II,I,III
C)III,II,I
D)III,I,II

Question 25

Fluorescence microscopy of intact organisms or large cells results in the generation of blurred images.Which of the following is NOT a technique that reduces the out-of-focus signal that causes blurring?

A)two-photon excitation microscopy
B)confocal microscopy
C)fluorescence recovery after photobleaching (FRAP)
D)deconvolution microscopy

Question 26

Describe how a Förster resonance energy-transfer (FRET)biosensor like cameleon,which consists of CFP linked to YFP by the protein calmodulin,can detect local changes in calcium ion concentration.For your information,CFP excites at 440 nm and emits at 480 nm,whereas YFP emits at 535 nm.

Question 27

Osmium tetroxide is commonly used to:

A)stain specimens for light microscopy.
B)coat specimens for metal shadowing electron microscopy.
C)stain specimens for transmission electron microscopy.
D)measure the Ca²⁺ concentration inside living cells.

Question 28

The disruption of a cell is necessary to release its organelles and contents for subsequent isolation.One method,called _____,uses ultrahigh-frequency sound to disrupt the cell plasma membrane.

A)tomography
B)epitope tagging
C)sonication
D)centrifugation

Question 29

A small tumor is excised from a patient's body.The pathologist wants to examine the number,size,and arrangement of cells within the tumor.The best technique to use would be:

A)DIC microscopy.
B)phase contrast microscopy.
C)bright-field microscopy after fixation,sectioning,and staining.
D)fluorescence microscopy.

Question 30

Centrifugation of homogenized tissue from a mouse liver at 15,000 × g for 5 minutes will pellet:

A)mitochondria
B)nuclei
C)plasma membrane
D)mitochondria and nuclei

Question 31

Fluorescence microscopy of cells that are labeled with a green fluorescent antibody against microtubules (a cytoskeletal component)differs from cells expressing green fluorescent protein (GFP)tagged to beta tubulin (a component of microtubules)in all the following ways EXCEPT:

A)the antibody labeled cells need to be permeabilized before visualization,while the GFP cells do not.
B)the microtubules could change their localization over time in the GFP cells,but not in the antibody labeled cells.
C)the GFP cells do not need to be treated with fixatives,but the antibody labeled cells do.
D)the antibody labeled cells will identify the microtubule structures,while the GFP will be observed in other places in the cell because it is not as specific as an antibody.

Question 32

Although many types of vesicles are similar in size and density,it is possible to isolate specific types of vesicles through the use of:

A)a fluorescent-activated cell sorting machine.
B)antibodies attached to bacterial carriers and low speed centrifugation.
C)ultracentrifugation.
D)light microscopy.

Question 33

If a cellular homogenate were subjected to differential centrifugation,which of the following would be expected to pellet first?

A)the endoplasmic reticulum
B)mitochondria
C)the cytosol
D)nuclei

Question 34

The enzymatic functions of specific organelles can best be examined:

A)in intact cells where the organelles are working as they normally would.
B)in cells that have been prepared for SEM (scanning electron microscopy).
C)in fractions taken from cell homogenates that have been separated by differential centrifugation.
D)in fractions taken from differential centrifugation of cellular homogenates that are further incubated with antibodies specific to the organelle under study,which can be used to precipitate the organelles away from contaminates.

Question 35

Rough endoplasmic reticulum can be separated from smooth endoplasmic reticulum by differential centrifugation.What is the basis for this fractionation?

Question 36

Proteomic studies allow for the identification of all proteins within an organelle,assuming the organelle can be purified sufficiently well.Proteomic analyses of mitochondria from different cell types revealed what interesting finding?

A)Mitochondrial proteins have all been identified over the years.
B)Mitochondria contain less than 40 different proteins.
C)Mitochondria in different cell types can contain different proteins.
D)Mitochondrial proteins cannot be examined using proteomic approaches.