Microbiology Lab Exam 1 Overview

Question 1

(4x) Scanning Objective

Answer 1

The shortest lens, 40 magnification level.

Question 2

(40x) High (power) Dry Objective

Answer 2

The next longest objective, 400 magnification level.

Question 3

(100x) Oil Immersion

Answer 3

The longest objective lens, 1000 magnification level.

Question 4

Ocular (eyepiece)

Answer 4

magnifies image of specimen 10x

Question 5

Body

Answer 5

the body contain mirrors that bend light into the oculars.

Question 6

Nosepiece

Answer 6

Holds the objectives and can be rotated to move the objective over the stage.

Question 7

Objectives

Answer 7

Contain lenses that magnify the image. 4x, 10x, 40x or (45x) and 100x.

Question 8

Arm

Answer 8

Support the nosepiece and hold the on/off toggle and the focus adjustment knobs.

Question 9

Stage/mechanical stage

Answer 9

Flat surface that support the slides. Usually has clips to hold the slide in place. Some have adjustment knobs to move slide.

Question 10

Stage adjustment knobs

Answer 10

located below the stage move the mechanical stage

Question 11

Light Intensity Control

Answer 11

Knobs increase or decrease light output from the light source.

Question 12

Substage condenser

Answer 12

made of at least two lenses that focus the light passing through the specimen and improve image sharpness

Question 13

Aperture diaphragm control

Answer 13

controls the amount of light entering the substage condenser from the light source

Question 14

Field Diaphragm Lever

Answer 14

opens and closes to increase and decrease light from the light source.

Question 15

Light Source

Answer 15

illuminator is a halogen bulb that produces light.

Question 16

Base

Answer 16

hold the illuminator and supports the rest of the microscope.

Question 17

Fine focus adjustment knob

Answer 17

this part moves the stage slightly to help you sharpen or “fine” tune your view of the specimen

Question 18

Coarse focus adjustment knob

Answer 18

moves the stage up and down by larger increments and allows you to bring the image into focus

Question 19

Magnification

Answer 19

the number of times the image is enlarged

Question 20

Resolution

Answer 20

the ability of a lens system to small, close-together objects as separate objects.

Question 21

Contrast

Answer 21

is the measure of the differences in appearance between two objects

Question 22

Adjusting the light

Answer 22

Passing through the specimen is another way to adjust contrast.

Question 23

Total Magnification

Answer 23

objective lens x ocular lens

Question 24

Parfocal Lens

Answer 24

maintain focus of a specimen as objective lenses are switched from one objective power to another

Question 25

Depth of field

Answer 25

thickness of the plane of focus

Question 26

Field of View

Answer 26

The area visible through the microscope eyepiece

Question 27

Working Distance

Answer 27

distance between the top of objective and the stage.

Question 28

How to view prepared slides: describe the process

Question 29

Aseptic Technique

Answer 29

method of handing microbes and materials in a way that minimizes contamination

Question 30

Inoculation

Answer 30

The process of transferring a microbe from on medium to the next.

Question 31

Inoculum

Answer 31

the sample being transferred

Question 32

inoculating loop/needle

Answer 32

tools used to transfer bacteria from a culture to sterile media

Question 33

Turbidity

Answer 33

A measure of how clear water is.

Question 34

Flocculent (bacteria growth)

Answer 34

flecks or chucks of bacterial growth

Question 35

Sediment (bacteria growth)

Answer 35

Where is the population of bacteria located

Question 36

Ring (bacteria growth)

Answer 36

Growth only around he edge

Question 37

Pellicle (bacterial growth)

Answer 37

thin film coating of bacteria covering the surface.

Question 38

Describe how you would inoculate a plate, broth, or slant using proper aseptic techniques.

Question 39

Describe how you would remove an inoculum

Question 40

Look at Review question Lab Report (2)

Question 41

Isolation Streak Plate

Answer 41

method to separate individual bacteria from mixtures.

Question 42

Isolated Colonies

Answer 42

small group of cells comes off the loop to form.

Question 43

Colony

Answer 43

arises from a single bacterium that divides repeatedly over time to form a mass of cells.

Question 44

first streak area

Answer 44

Heavy confluent growth

Question 45

Second streak area

Answer 45

Growth is starting to thin out and some individual colonies are starting to appear

Question 46

Third Streak area

Answer 46

thinner growth and isolated colonies appear

Question 47

How would you perform an isolation streak?What results would you expect to see?