This set of Cell Biology test focuses on “Studying the Cytoskeleton”.
1. Which protein is used for the fluorescent labeling of cytoskeleton elements of the cell?
a) horseradish peroxide
b) methylene blue
c) bromophenol blue
d) green fluorescent protein
Explanation: The green fluorescent protein (26.9 kDa) is used to synthesize fusion proteins in the cell. In this way proteins of the cytoskeletal elements can be fluorescently labeled and then studied.
2. In fluorescence speckle microscopy, cytoskeletal filaments are uniformly labeled.
Explanation: Fluorescently labeled proteins are microinjected or expressed in living cells in the technique of fluorescence speckle microscopy. All the proteins of the cytoskeletal filaments are not uniformly labeled.
3. Variants of a protein are called __________
Explanation: In fluorescence microscopy, proteins can be labeled using antibodies and it is possible to distinguish between closely related variants of proteins called the isoforms.
4. Which types of lasers are used in optical tweezers?
a) Laser beams
d) Radio waves
Explanation: Microscopic beads attached to specific proteins can be placed directly on a specific cell organelle using laser beams. This grasps microscopic objects and is referred to as optical tweezers.
5. In total internal reflection microscopy (TIRF), thin planes can be focused
Explanation: Total internal reflection microscopy (TIRF) is a specialized type of laser-based fluorescence microscopy, which allows the focusing of very thin planes. As a result, fluorescent light rays emanating from the field of view do not obscure the specific proteins being monitored.
6. Atomic force microscopy uses _____________
b) Infrared light
c) Nanosized tip
d) Nickel tip
Explanation: Atomic force microscopy is a type of high resolution scanning probe microscopy that uses the nanosized tip to probe the surface of a macromolecule. Researchers have used this technique to study intermediate filaments.
7. Which of the following are the most extensible filaments?
a) intermediate filaments
Explanation: The most extensible cytoskeletal filaments are the intermediate filaments. They can be mechanically stretched to 3.5 times its original length.
8. Which technique has been used to study the dynamic nature of microtubules?
Explanation: Fluorescence recovery after photobleaching (FRAP) is a technique that has been used by the researchers to study the dynamic properties of microtubules. In a FRAP experiment, the cell is either injected with fluorescently labeled tubulin or induced to express GFP-tubulin.
Sanfoundry Global Education & Learning Series – Cell Biology.
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