Microscopy

Question 1

Who produced the first operational compound microscope with a magnification of 30x

Answer 1

Janssens

Question 2

Who described cork and other cells and introduced the term cell

Answer 2

Hooke

Question 3

What did Bichat do?

Answer 3

recognized 21 kinds of membranes (tissues) but did not use microscope

Question 4

who formed the cell theory

Answer 4

Mirbel, Turpin, Virchow

Question 5

Who came up with the free cell formation theory

Answer 5

Schleiden

Question 6

what is the free cell formation theory

Answer 6

cell is essential unit of the living organism (idea that cells arise by budding from the nucleus)

Question 7

Define refraction of light

Answer 7

bending of light waves

Question 8

what is the equation for refractive index

Answer 8

velocity of light/velocity of light inside transmitting medium

Question 9

what does the degree of bending depend on in optics

Answer 9

Refractive Index

angle at which light strikes surface

Question 10

what is refractive power

Answer 10

measure of how much a lens bends light waves. measures in diopters

Question 11

define focal point

Answer 11

point through which all parallel rays of light will pass after passing through each part of the lens

Question 12

define focal length

Answer 12

distance from the center of the lens to the focal point

Question 13

name characteristics of real image

Answer 13

object is outside focal point
real image is inverted
real image can be projected onto a screen
real image differs in size from the object

Question 14

name characteristics of virtual image

Answer 14

object is placed inside the focal point
virtual image is not inverted
virtual image cannot be projected onto a screen
virtual image can be magnified

Question 15

define resolution

Answer 15

ability of a microscope to distinguish 2 small points as separate points

Question 16

what are the components of a compound optical (light) microscope

Answer 16

light source
condenser
stage
objective lens
ocular lens

Question 17

what are the pros of compound optical (light) microscopes

Answer 17

ability to magnify

ability to resolve structural detail

Question 18

what are the cons of compound optical (light) microscopes

Answer 18

specimen must be thin

relatively little contrast in the unstained specimen

Question 19

what do phase contrast microscopes do

Answer 19

converts phase shifts in light passing through a transparent specimen to brightness changes in the image

Question 20

what is phase contrast microscopes particular useful for examining

Answer 20

unstained cells and tissues
living cells
(used more for research than medical application)

Question 21

what do fluorescence microscopes do

Answer 21

detects molecules that emit light of wavelengths in the visible range when exposed to a UV light source

Question 22

give examples of how fluorescence microscopes are used

Answer 22

detection of antigens or antibodies in immunochemical staining procedures
detection of fluorescent tracers injected into animals or cells

Question 23

what microscope allows for the reconstruction of 3D images

Answer 23

confocal scanning microscope

Question 24

name some advantages of confocal scanning microscopes

Answer 24

very thin optical images of the specimen are created
out of focus images are subtracted from the image by the computer program
computer can make 3D reconstructions of the specimen by stacking individual images

Question 25

what are the components of transmission electron microscopes

Answer 25

cathode
heated tungsten filament
anode
series of electromagnets: condenser lens, objective lens, projection lens
specimen holder
viewing screen and photographic film