36 Questions
What term was used by Van Leeuwenhoek to describe microbes?
Animalcules
What is the term for the measure of how greatly a substance slows light?
Refractive index
What is the purpose of oil in light microscopy?
To get better resolution and achieve 1000x magnification
What is the process of preparing bacteria for observation by attaching them to a slide?
Heat fixing
What is the term for the distance between the center of the lens and the focal point?
Focal length
Why is gram staining necessary for observing bacteria?
Because bacteria have no color
What is the result of light moving into a different medium?
It gets detracted
What is the purpose of the objective lens in a compound microscope?
To bend the light
What is the significance of Louis Pasteur's work in relation to spontaneous generation?
He disproved that spontaneous generation occurs
What is the purpose of chemical fixation in preparing bacterial samples for microscopy?
To preserve the structure of the cell
Why do some bacteria, such as those that cause tuberculosis, require special staining procedures?
Because they have high lipid content in their cell walls
What is the purpose of the iodine step in the Gram staining procedure?
To bind to the peptidoglycan layer
What type of microscopy is used to visualize live bacteria without staining?
Phase-contrast microscopy
What is the purpose of the filters in fluorescence microscopy?
To remove long wavelengths
What is the advantage of using confocal microscopy?
It provides a three-dimensional image
Why is it necessary to dehydrate and fix samples for transmission electron microscopy (TEM)?
To allow for the beam of electrons to pass through
What is the difference between TEM and scanning electron microscopy (SEM)?
TEM is used for studying internal structures, while SEM is used for studying surface structures
What is the advantage of cryotomography over other types of microscopy?
It does not require fixation or dehydration
What is the primary reason why bacteria need to be stained for observation under a light microscope?
Because they have no color
What is the purpose of the objective lens in a compound microscope?
To focus the light on the sample
What is the result of using a shorter focal length in a microscope?
Greater magnification
Why is oil needed for high-magnification microscopy?
To achieve a resolution of 1000x magnification
What is the significance of Louis Pasteur's work?
He disproved the theory of spontaneous generation
What is the term used to describe the measure of how greatly a substance slows light?
Refractive index
What is the purpose of heat fixing bacteria to a slide?
To attach the bacteria to the slide
What is the term used to describe the bending of light as it passes through a different medium?
Refraction
What is the significance of Van Leeuwenhoek's work?
He was the first to describe microbes
What is the primary reason for using acid to treat certain bacteria before Gram staining?
To break down the high lipid content in the cell wall
What is the main difference between basic and acidic dyes in bacterial staining?
Basic dyes have a positive charge and acidic dyes have a negative charge
What is the purpose of the heat fixation step in Gram staining?
To adhere the bacteria to the slide
What is the main advantage of using fluorescence microscopy for bacterial observation?
It enables the visualization of specific structures or molecules within the bacteria
What is the main difference between TEM and SEM?
TEM is used for observing the internal structure of bacteria, while SEM is used for observing the surface of bacteria
What is the purpose of the counterstain step in Gram staining?
To enhance the differentiation of Gram-positive and Gram-negative bacteria
Why are some bacteria resistant to heat fixation?
Because they have endospores
What is the primary advantage of using confocal microscopy for bacterial observation?
It enables the visualization of three-dimensional structures within the bacteria
What is the main advantage of using cryotomography for bacterial observation?
It enables the visualization of internal structures without the need for fixation
Explore the history of microbiology, from Van Leeuwenhoek's discovery of microbes to the development of vaccines and antibiotics. Learn about various forms of light microscopy and their applications in forensic analysis.
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