Bio1000 Lab 2

light source

an attached lamp that directs a beam of light up through the object

Transmission Electron Microscope (TEM)

analogous to the compound light microscope; object is thinly sliced and treated with heavy metal salts to improve contrast

Scanning Electron Microscope (SEM)

analogous to the dissecting light microscope; gives the image of the surface and dimensions of an object, as is apparent from the scanning electron micrograph

depth of field

area from top to bottom that comes into focus while slowly focusing up and down with the microscope's fine adjustment knob

what was the order of the threads from top to bottom

blue, red, and yellow

How is total magnification calculated?

by multiplying the magnification of the ocular lens (eyepiece) by the magnification of the objective lens

field of view

circle visible through the lenses

stage clips

clips that hold a slide in place on the stage

cross section (cs)

crosswise cut through any type of specimen

if the threads are layered top to bottom, brown, green, red, which layer will come into focus first if you are using the microscope properly--what's the term related to this process

depth of perception

which type of microscope should be used to view a virus that's 50nm in size

electron microscope

if a slide is being viewed with a high-power objective, which adjustment knob should be used to sharpen the focus

fine focus

which has a smaller field but magnifies to the greatest extent

high power

viewing head

holds the ocular lenses

Photomicrographs/light micrographs

images produced by a compound light microscope

If the amount of light passing through the condenser needs to be decreased, what microscope part should be adjusted?

iris diaphragm

fine adjustment knob

knob used to bring an object into final focus

coarse adjustment knob

knob used to bring object into approximate focus; used only with low-power objective

diameter of field

length of the field from 1 edge to the other

longitudinal section (ls)

lengthwise cut through any type of specimen

low power objective

lens is longer than the scanning objective lens and is used to view objects in greater detail; 10x

condenser

lens system below the stage used to focus the beam of light on the object being viewed

Diaphragm/control lever

lever that controls the amount of light passing through the condenser

if you use the coarse-adjustment knob to focus on an object with the high-power objective, what problems will you encounter; explain

limited view; every time you raise the magnification, the magnification view lowers

high power objective

longest; used to view an object in even greater detail; 40x

Does low power or high power have a larger field of view? (one that allows you to see more of the object)

low power

to locate small objects on a slide, first find them under ____ then place themin the center of the girld before rotating to

low; high

to properly measure 20ml of water, what must be at the 20ml mark of the graduated cylinder

meniscus reading

length consists of

meter, centimeter, millimeter, micrometer, and nanometer

resolution

minimum distance between 2 objects at which they can be seen/resolved as 2 separate objects; the use of high energy electrons rather than light gives electron microscopes a much greater resolving power since 2 objects that are much closer together can still be distinguished as separate points

what is the name for the lenses located near the eye

ocular

parfocal

once the object is in focus with the lowest power, it should also be almost in focus with the higher power

what word describes a microscope that remains in focus when the objective lenses are changed

parfocal

stage

platform that holds and supports the microscope slides; movable that aids in the accurate positioning of the slide

wet mount

prepared by placing a drop of liquid on the slide or if the material is dry, by placing it directly on the slide and adding the drop of water or stain; then covered with a cover-slip; dry the bottom of the slide before placing on stage

nosepiece

revolving device that holds objectives

If Euglena are swimming to the left, which way should you move your slide to keep them in view?

right

what kind of microscope would be used to study a whole or opaque object

scanning

which objective should be in place when the microscope is put away

scanning

scanning objective

shortest of objective lenses and is used to scan the whole slide; magnification is stamped on the housing of the lens; #x; 4x

metric system

standard system of measurement in the sciences; all conversions whether volume, mass/weight, or length can be in units of 10

arm

supports upper parts and provides carrying handle

base

the flat surface of the microscope that rests on the table

High power diameter of field (HPD) equation

HPD (high power diameter of field) = LPD (low-power diameter of field) x [LPM (low-power total magnification) /HPM (high-power total magnification)

euglena

unicellular organism with a flagella to facilitate movement

what were some observations in the inversion experiment?

upside down; when moving to the right, the image moves left; when moving it toward us, the image moves away from us; vice versa

electron microscopes

use beams of electrons to magnify the object; the beams are focused on a photographic plate by means of electromagnets

compound

use of 2 sets of lenses: the ocular lens located near the eyes and the objective lens near the object; illumination is from the below, and visible light passes through clear portions but doesn't pass through opaque portions; to improve contrast, the microscopic uses stains/dyes that bind the cellular structures and absorb light

compound light microscope

used for examining small or thinly sliced sections of objects under higher magnification

compound light microscope and transmission electron microscope

views extremely thin sections of a specimen

stereomicrope/dissecting and scanning electron microscope

views the surface and/or the 3 dimensional structure of the object; dissecting= study objects in 3D at low magnification

if the total magnification of a slide is 400x and the ocular lenses are 10x what's the magnifying power of the objective being used

40x

how many m and cm in a mm

1.0mm= 10^-3m= 0.1cm

oil immersion objective

100x lens and is used in conjunction with immersion oil to view objects with the greatest magnification

micrometer=

10^-6m, 10^-4cm, 10^-3mm

nanometer=

10^-9m, 10^-7cm, 10^-6mm

Eyepiece/ocular lenses

10x

how many m and mm in a cm

1cm= 10^-2m = 10mm

how many cm and mm in a meter

1m= 100cm= 1000mm

mechanical stage control knobs

2 knobs that control forward/reverse movement and right/left movement