BIOL 2070 Chapter 2: Chapter 2

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orangehorse801

7 Feb 2017

School

University of Windsor

Department

Biological Sciences

Course

BIOL 2070

Professor

tanyanoel

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Document Summary

The science of microbiology has taken its greatest leaps forward as new tools are developed and new tool are improved. Microscope is oldest and most basic tool. To see microorganisms, one needs a microscope of some sort. In general, light microscopes are used to examine cells at relatively low magnifications, and electron microscopes are used to examine cells and cell structures at very high magnification. All microscopes employ lenses that magnify the image. Magnification is not the limiting factor in our ability to see small objects. Resolution the ability to distinguish two adjacent objects as distinct and separate governs out ability to see the very small. Although magnification can be increased virtually without limit, resolution cannot, because resolution is a function of the physical properties of light. For the light microscope, the limits of resolution are about 0. 2 micrometers, while that of the electron microscope is considerably greater. Light microscope uses visible light to illuminate cell structures.

Related Questions

QUESTION 4

A substance that reacts the same to light polarized in any direction is _________________.

	a.	an isotope
	b.	anisotropic
	c.	isotropic
	d.	divergent

QUESTION 5

The part of the comparison microscope that allows the examiner to view two objects simultaneously is called the _________________.

	a.	comparator
	b.	comparison bridge
	c.	spectroscope
	d.	stage

QUESTION 6

A stereo microscope can best be described as _____________________.

	a.	Two compound microscopes aligned so that they each see a slightly different part of an object.
	b.	Two compound microscopes aligned with a comparison bridge.
	c.	A compound microscope with two separate stages and one ocular.
	d.	A compound microscope with two eyepieces and a camera mount.

QUESTION 7

In microscopy, resolution is a measure of ________________.

	a.	The ability of the lenses to separate two tiny details that are close together.
	b.	The total magnification power of the microscope.
	c.	The empty magnification power of the microscope.
	d.	The ability of an electron microscope to determine the presence of a large number of elements.

QUESTION 8

Two polarizers (polarizing filters) aligned 90Â° from each other will block out all light.

True

False

QUESTION 9

A simple convex lens creates a magnified real image of an object.

True

False

QUESTION 10

A trinocular microscope has three objective lenses mounted on a turret.

True

False

QUESTION 11

Liquids and gases are usually isotropic.

True

False

QUESTION 12

Match each of the following terms with Its Definition

Compound microscope a. Has a polarizer and an analyzer

Electron microscope b. Permits viewing two objects at once

Stereomicroscope c. Consists of a single convex lens

Comparison microscope d. Long working distance, three-dimensional

Simple hand magnifier e. Basic 2 convex lens microscope

Polarizing microscope f. Can magnify images more than 100,000 times

limecheetah620

QUESTION 1

The ocular of a compound microscope has a magnification of 10x and the objective has a magnification of 10x. The total magnification of the microscope is ___---

	a.	10x
	b.	20x
	c.	100x
	d.	1000x

QUESTION 2

The part of the microscope that focuses the light on an object is the ___________.

	a.	Iris Diaphragm
	b.	Coarse Focus
	c.	Condenser
	d.	Body Tube

QUESTION 3

The polarizing filter in a PLM that is located above the objective is called the _________________.

	a.	Polarizer
	b.	Analyzer
	c.	Abbe condenser
	d.	Iris

QUESTION 4

A substance that reacts the same to light polarized in any direction is _________________.

	a.	an isotope
	b.	anisotropic
	c.	isotropic
	d.	divergent

QUESTION 5

The part of the comparison microscope that allows the examiner to view two objects simultaneously is called the _________________.

	a.	comparator
	b.	comparison bridge
	c.	spectroscope
	d.	stage

1 points

QUESTION 6

A stereo microscope can best be described as _____________________.

	a.	Two compound microscopes aligned so that they each see a slightly different part of an object.
	b.	Two compound microscopes aligned with a comparison bridge.
	c.	A compound microscope with two separate stages and one ocular.
	d.	A compound microscope with two eyepieces and a camera mount.

QUESTION 7

In microscopy, resolution is a measure of ________________.

	a.	The ability of the lenses to separate two tiny details that are close together.
	b.	The total magnification power of the microscope.
	c.	The empty magnification power of the microscope.
	d.	The ability of an electron microscope to determine the presence of a large number of elements.

QUESTION 8

Two polarizers (polarizing filters) aligned 90Â° from each other will block out all light.

True

False

QUESTION 9

A simple convex lens creates a magnified real image of an object.

True

False

QUESTION 10

A trinocular microscope has three objective lenses mounted on a turret.

True

False

QUESTION 11

Liquids and gases are usually isotropic.

True

False

QUESTION 12

Match each of the following terms with Its Definition

Compound microscope a. Has a polarizer and an analyzer

Electron microscope b. Permits viewing two objects at once

Stereomicroscope c. Consists of a single convex lens

Comparison microscope d. Long working distance, three-dimensional

Simple hand magnifier e. Basic 2 convex lens microscope

Polarizing microscope f. Can magnify images more than 100,000 times

maroonmuskrat824

Scenario 2:
You are trying to resolve the 3-dimensional organization of some sub-cellular organelle or protein distributed throughout the cytosol of a cell. The objects are typically organized spatially with sizes of ~0.5Î¼m diameters or separation. In this situation the sample can be fixed (i.e. no constraint on image time), but it may be advantageous to image live samples as well (i.e. some constraint on image time), so the ability to image each type of sample needs to be considered. Issues to consider include limits of 3-dimensional spatial resolution and ways to overcome this, including within live moving cells such as time and photodamage effects.

The scenario above describes commonly encountered problems in applying fluorescence microscopy to study biological samples. I would like you to discuss ways of overcoming the problems at hand.

The problems that needs to be overcome:

-What is the cause of the fundamental limitation(s) present in the problem when using a conventional fluorescence microscope system (wide field microscope or regular confocal microscope)? What are the tradeoffs (e.g. photobleaching, acquisition speed, spatial resolution, signal, noise and background, or other factors) that provide practical limitations?

-What type of optical imaging approach, technology or strategy could overcome these problems?

-What light source, optical detector, fluorophore and other key instrumentation/reagents will be needed and why? (you may want to provide specs for specific products where relevant).
-How will this strategy work and how will it generate new information about the object/process being studied: e.g. will fluorescence intensity be measured, or fluorescence lifetime, or scattering, some other property?

-What other limitations could there be in the approach planned? Can these also be minimized and how?

champagnesea-lion818

BIOL 2070 Chapter 2: Chapter 2

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