Interactions of Light with Objects

What is resolution in microscopy?

The smallest distance by which two objects can be separated and still be distinguished

Which type of microscopy is the simplest?

Light microscopy

What is detection in terms of observing microbes?

Determining the presence of an object

What is magnification in microscopy?

An increase in the apparent size of an image to resolve smaller separations between objects Signup and view all the answers

What range of sizes do eukaryotic microbes like protozoa, algae, and fungi typically fall within?

2 µm–20 cm Signup and view all the answers

What is the main purpose of a simple stain in microbiology?

Add dark color specifically to cells Signup and view all the answers

Which technique is used to differentiate between Gram-positive and Gram-negative bacteria?

Gram Stain Signup and view all the answers

What happens during fluorescence microscopy in terms of light absorption and emission?

Specimen absorbs light of defined wavelength and emits light of lower energy Signup and view all the answers

Which staining technique is known for staining different types of cells to distinguish them from each other?

Differential Stain Signup and view all the answers

What is the function of a counterstain in the Gram stain technique?

To stain Gram-negative bacteria red or pink Signup and view all the answers

What is the typical size range of prokaryotes?

0.4–10 µm Signup and view all the answers

What are common shapes seen in bacteria?

Bacilli and cocci Signup and view all the answers

What are the key conditions needed for electromagnetic radiation to resolve an object?

Contrast between object and medium, smaller wavelength than the object Signup and view all the answers

What is the wavelength range of visible light?

~400–750 nm Signup and view all the answers

How small must the wavelength be compared to the object for electromagnetic radiation to resolve it?

Smaller than the object Signup and view all the answers

What does absorption of light by an object mean?

The object acquires the photon's energy Signup and view all the answers

In the context of light interacting with an object, what does refraction refer to?

The bending of light as it slows down when entering a substance Signup and view all the answers

Why does magnification require the bending of light rays?

To bend the rays in order for them to intersect at a focal point Signup and view all the answers

How does a compound microscope compensate for aberration?

By having ocular and objective lenses with different magnifications Signup and view all the answers

How is the detection and resolution of cells under a microscope enhanced?

By making cells adhere to a slide in a fixed position Signup and view all the answers