Optics and Microscopy Quiz

False (B)

'micro' and 'scope'

<p>focal length</p> Signup and view all the answers

<p>Refractive index = Measure of how much a medium slows light Focal point = The specific point where a convex lens focuses parallel rays of light Microscopy = Science of using microscopes Focal length = Distance between the center of the lens and the focal point</p> Signup and view all the answers

<p>It converges incoming parallel light rays (D)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>microscope</p> Signup and view all the answers

<p>40x to 1000x (C)</p> Signup and view all the answers

<p>They appear widely separated. (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>condenser</p> Signup and view all the answers

<p>ultraviolet</p> Signup and view all the answers

<p>1.00 (B)</p> Signup and view all the answers

<p>1</p> Signup and view all the answers

<p>Dark-field microscopy (D)</p> Signup and view all the answers

<p>Light Microscope = Uses visible light and lenses Transmission Electron Microscope (TEM) = Transmits electrons through a specimen Scanning Electron Microscope (SEM) = Scans a focused electron beam over the surface of a sample</p> Signup and view all the answers

<p>immersion oil</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>To control the amount of light passing through the sample</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Simple Microscope = A single lens magnifying glass Compound Microscope = Two sets of lenses: an objective and an eyepiece</p> Signup and view all the answers

<p>Compound microscope (A)</p> Signup and view all the answers

<p>Longer wavelength and lower energy (C)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>fluorophores or fluorochromes</p> Signup and view all the answers

<p>barrier</p> Signup and view all the answers

<p>Fluorophores = Dye molecules used in fluorescence microscopy Exciter Filter = Transmits only the desired wavelength of light in fluorescence microscopy Barrier Filter = Removes unwanted ultraviolet, blue, or violet light in fluorescence microscopy Electron Microscopy = Technique that uses a beam of electrons to create an image</p> Signup and view all the answers

<p>Mercury vapor arc lamp (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM)</p> Signup and view all the answers

<p>Analyzing the chemical composition of cellular membranes (C)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>To prevent the buildup of an electrical charge on the surface and to give a better image.</p> Signup and view all the answers

<p>sublimate</p> Signup and view all the answers

<p>Cells are rapidly frozen in liquid nitrogen = Freeze-etching Specimen is shadowed and coated with platinum and carbon = Freeze-etching Samples are mounted and coated with a thin layer of metal = Specimen Preparation for SEM Specimen must first be fixed, dehydrated, and dried = Specimen Preparation for SEM</p> Signup and view all the answers

<p>0.005 nm (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>magnetic lenses</p> Signup and view all the answers

<p>High vacuum (A)</p> Signup and view all the answers

<p>secondary electrons</p> Signup and view all the answers

<p>To emit light flashes when struck by electrons. (C)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Transmission Electron Microscope (TEM) = To produce an image from radiation that has passed through a specimen Scanning Electron Microscope (SEM) = To produce an image from electrons emitted by an object's surface</p> Signup and view all the answers

The science of using microscopes to view tiny objects.

An optical instrument containing multiple lenses that enlarge the image of tiny objects.

The act of light bending as it passes from one medium to another.

How much a material slows down the speed of light.

A line perpendicular to the surface where light passes from one medium to another.

Point where parallel light rays converge after passing through a convex lens.

The distance between the center of a lens and its focal point.

A shorter focal length means stronger magnification.

The ability of a microscope to distinguish two closely spaced objects as separate.

The angle of the cone of light that enters the objective lens from a specimen.

A measure of the light-gathering ability of a lens, calculated as n sin θ (where n is the refractive index and θ is the angular aperture).

A colorless liquid with a refractive index similar to glass, used to increase the NA of a microscope lens.

A type of microscope that uses a single lens to magnify an object.

A type of microscope that uses two sets of lenses - the objective lens and the eyepiece - to magnify an object.

The ability of a lens to bend light rays. A higher refractive index allows more light to enter the lens.

The distance between the objective lens and the specimen when the specimen is in focus.

A specialized type of microscope that uses a beam of electrons to illuminate and magnify a specimen.

A type of electron microscope where the electron beam passes through the specimen, creating an image from the transmitted electrons.

A type of electron microscope that uses a focused beam of electrons to scan the surface of a specimen.

A type of electromagnet used to focus the electron beam in an electron microscope.

Electrons emitted from the surface of a specimen when it is bombarded with an electron beam.

A material that emits light when struck by an electron beam.

A device used to detect and amplify light signals produced by a scintillator, converting them into an electrical signal.

A microscope that uses visible light and lenses to magnify objects. Magnification typically ranges from 40x to 1000x.

The lens you look through in a light microscope, typically with a 10x magnification.

Multiple lenses in a light microscope that provide different magnifications, typically 4x, 10x, 40x, and 100x.

A flat surface in a light microscope where the slide with the specimen is placed.

A component in a light microscope that focuses light onto the specimen.

A device in a light microscope that controls the amount of light passing through the sample.

Knobs in a light microscope that adjust the sharpness of the image, allowing clear focus.

A light source, typically a lamp, that illuminates the sample in a light microscope.

A type of light microscopy where the light passes directly through the specimen, creating a dark image against a bright background.

A type of light microscopy where light is directed at an angle to the sample, resulting in a bright image against a dark background.

A type of light microscopy that enhances contrasts in transparent specimens, making them easier to study.

A type of light microscopy using UV light to excite fluorophores attached to specimens, making them appear brightly colored.

A technique for studying internal structures of microorganisms by rapidly freezing cells in liquid nitrogen, fracturing them, and then coating the exposed surfaces with platinum and carbon to create a replica for visualization under a transmission electron microscope (TEM).

A method for preparing specimens to be viewed under a scanning electron microscope (SEM). It involves fixing, dehydrating, and drying the sample to preserve its surface structure. Then, a thin layer of metal, usually gold, is coated onto the specimen to improve image quality.

A special procedure used to study the three-dimensional structure of internal cell components like organelles, bacteria, and viruses.

Maintaining the shape and integrity of structures within the sample.

To prevent the build-up of electrical charge on the specimen's surface, enhancing image quality in the SEM.

The process where a substance absorbs light energy and then emits light of a longer wavelength (lower energy). This is used in microscopy to visualize specimens.

Fluorescent molecules, like dyes used in microscopy, absorb light of a specific wavelength and emit light of a longer wavelength.

In fluorescence microscopy, the specimen is illuminated with light of a specific wavelength (e.g., ultraviolet, violet, or blue) which is absorbed by the fluorophores, causing them to emit light of a longer wavelength that is then used to form an image.

A mercury vapor arc lamp is used as a light source in fluorescence microscopy. Infrared filters are used to reduce heat transfer, and exciter filters allow only the desired wavelength of light to pass through.

Electron Microscopy uses a beam of electrons to create an image of a specimen. It has much higher resolution than light microscopy, allowing for the visualization of smaller structures.

There are two main types of electron microscopy: Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). TEM transmits electrons through the specimen, while SEM scans a focused beam of electrons across its surface.

In microscopes, higher resolution is achieved using light of shorter wavelengths. This is because shorter wavelengths interact with smaller structures more effectively.

Electron beams behave like radiation and can be focused, making them suitable for use in electron microscopy, where they act as the illumination source.