A. 47:49 What is unique about the pictured tissue?
Multiple Choice
a) It can change shape.
b) It doesn’t tear.
c) It stains with striations.
d) It can conduct electricity.
B. A stained specimen of bacteria to study morphology A specimen of virus A stained specimen to study the surface of a plasma membrane An unstained plant sample with chloroplasts TI A stained sample with immunofluorescence using two different fluorescent dyes E Phase-contrast E TEM E Scanning E Fluorescent = Bright-field
The Correct Answer and Explanation is :
Part A: What is unique about the pictured tissue?
Correct Answer: a) It can change shape.
Explanation:
The tissue in question is likely transitional epithelium, a specialized type of epithelial tissue. This tissue is found in the urinary bladder, ureters, and parts of the urethra. Its unique property is its ability to stretch and change shape depending on the organ’s state.
For instance:
- When the bladder is empty, the cells appear cuboidal or rounded.
- When the bladder fills with urine and stretches, the cells flatten and appear squamous.
This ability allows transitional epithelium to accommodate fluctuations in volume without tearing or losing its protective barrier function. Other options like “stains with striations” (seen in striated muscles), “doesn’t tear” (general property of many tissues), and “conducts electricity” (a property of nerve and muscle tissue) do not describe transitional epithelium.
Part B: Matching the Sample with the Correct Microscopy Technique
- A stained specimen of bacteria to study morphology
Correct Answer: Bright-field Microscopy.
Bright-field microscopy is commonly used for viewing stained specimens, such as bacterial slides, to observe shapes like cocci, bacilli, or spirilla. The staining enhances contrast against the background. - A specimen of a virus
Correct Answer: TEM (Transmission Electron Microscopy).
Viruses are too small to be resolved with light microscopy. TEM provides high-resolution images of the internal structures of viruses. - A stained specimen to study the surface of a plasma membrane
Correct Answer: Scanning Electron Microscopy (SEM).
SEM provides detailed three-dimensional images of surfaces, including the plasma membrane, when stained or coated with a conductive material. - An unstained plant sample with chloroplasts
Correct Answer: Phase-contrast Microscopy.
Phase-contrast microscopy enhances contrast in transparent, unstained specimens, making it ideal for visualizing chloroplasts. - A stained sample with immunofluorescence using two different fluorescent dyes
Correct Answer: Fluorescent Microscopy.
Fluorescent microscopy uses specific wavelengths of light to excite fluorescent dyes, enabling visualization of multiple components in a sample.
Key Points:
- Bright-field: Best for stained samples.
- Phase-contrast: Ideal for living, unstained samples.
- SEM: Best for surface details.
- TEM: Best for internal structures at the ultrastructural level.
- Fluorescent Microscopy: Highlights specific molecules using fluorescent dyes.