Lecture 3 Examination Of Microorganisms

Question 1

The technical field of using
microscopes to view
samples & objects that
cannot be seen with the
unaided eye (objects that
are not within the
resolution range of the
normal eye).

Answer 1

Microscopy

Question 2

Generally, light is passed
from a source through a
condenser to focus it on the
sample to have maximum
brightness then it goes
through the objective lens to
magnify the image of the
sample & then to the oculars,
where the enlarged image is
viewed.

Answer 2

Compound Microscope

Question 3

further magnifies the
object and forms a real image
Magnification: 10X

Answer 3

Ocular lens

Question 4

Initially magnifies object-form real
image

Answer 4

objective lenses

Question 5

Magnifications of objective lenses?

Answer 5

• Scanning objective –4x
• Low Power Objective (LPO) –10x
• High Power Objective (HPO)–40x
• Oil immersion objective (OIO) – 100x

Question 6

Product of the magnifying powers of the objective
and ocular lenses

Answer 6

Total Magnification of the microscope:

Question 7

Total magnification of objective lenses

Answer 7

• LPO –10 x 10 = 100 times
•HPO–40 x 10 = 400 times
•OIO – 100 x 10 = 1000 times

Question 8

Is the product of the magnifying
powers of the ocular (eyepiece) and the objective
lens.

Answer 8

Magnification

Question 9

The shortest distance between two
points on a specimen that can still be distinguished
by observer, camera or lens of the microscope.

Answer 9

Resolution

Question 10

Is a
technique used to increase the
resolving power of a microscope.

Answer 10

oil immersion

Question 11

can be increased without
limit but not resolution because it is
dictated by the physical properties of
light (i.e. wavelength)

Answer 11

Magnification

Question 12

a specimen viewed
through a microscope can be
increased by changing the objective
lens to a higher magnification (eg.
from LPO to HPO).

Answer 12

resolution

Question 13

affords/gives
higher resolution

Answer 13

Shorter wavelength light

Question 14

is the measure of its ability
to gather light and to
resolve fine specimen
detail while working at a
fixed object (or specimen)
distance.

Answer 14

numerical aperture of a
microscope

Question 15

True or false

The higher the
numerical aperture, the
higher the resolving
power of a lens

Answer 15

True

Question 16

Numerical aperture values
are marked as _____ in the
objective lenses

Answer 16

N.A.

Question 17

Light bending
ability of a medium. Ordinary light has
lower refractive index while
cedarwood oil has higher refractive
index.

Answer 17

Refractive index

Question 18

Types of microscope

Answer 18

Light microscopes
1.simple
2.compound
3.Stereo, stereoscopic or
dissecting microscope
4.Phase contrast microscopes
5. Fluorescence microscopes
6.Atomic force microscopes
(AFM)
7.Confocal Scanning Laser Microscopes (CSLM)
8.Electron microscopes

Question 19

Types of Microscopes use
visible light to illuminate cell
structures/specimens

Answer 19

Light microscope

Question 20

Type of light microscope?

Answer 20

Simple and compound light microscope

Question 21

Types of light compound microscope?

Answer 21

-bright-field microscopes
-background dark-field
microscopes

Question 22

Types of light compound microscopes
based on type of illumination where specimen appear dark
against a light

Answer 22

bright-field microscopes

Question 23

Types of light compound microscopes
based on type of illumination where specimen
appears bright against a
dark background

Answer 23

background dark-field
microscopes

Question 24

Types of microscope where is an optical microscope variant designed
for low magnification observation of a
sample, typically using light reflected from
the surface of an object rather than
transmitted through it.

Answer 24

Stereo, stereoscopic or
dissecting microscope

Question 25

Types of Microscope where enhances contrasts
of transparent and colorless objects by influencing
the optical path of light

Answer 25

Phase contrast microscopes

Question 26

Types of Microscope where are used to study
specimens, which can be made to fluoresce.

Answer 26

Fluorescence microscopes

Question 27

Types of Microscope where is a very high-
resolution type of scanning
probe microscope

Answer 27

Atomic force microscopes
(AFM)

Question 28

Types of Microscope where can investigate the
topological surfaces of
biological objects, from
whole cells to protein
particulates and other
materials

Answer 28

Atomic force microscopes
(AFM)

Question 29

Types of microscope where it obtains high-resolution optical images with depth
selectivity)

Answer 29

Confocal Scanning Laser Microscopes (CSLM)

Question 30

Types of microscope where it – employ a beam of
electrons instead of a beam of light;
- afford a resolution as much as 1000 fold higher than
the light microscopes
- Magnification as high as 100,000 to 200,000 as
compared to 1000x to 1500x of light microscopes

Answer 30

Electron microscopes

Question 31

Types of electron microscope?

Answer 31

1. transmission electron
   microscopes (TEM)
2. scanning electron
   microscopes (SEM)

Question 32

Types of electron microscope where used to study internal cell
structures or
ultramicroscopic entities
such as viruses and viroids

Answer 32

transmission electron
microscopes (TEM)

Question 33

Types of electron microscope where used to study internal cell
structures or
ultramicroscopic entities
such as viruses and viroids

Answer 33

transmission electron
microscopes (TEM)

Question 34

Types of electron microscope where used if only external
features of cells need to be
observed

Answer 34

scanning electron
microscopes (SEM)