Module 2.1 Microscopy Flashcards Preview

Biology Griffiths Y12 > Module 2.1 Microscopy > Flashcards

Flashcards in Module 2.1 Microscopy Deck (28):
1

What makes up a compound microscope

The objective lens which is placed near to the specimen, and an eyepiece lens, through which the specimen is viewed.

2

What does the objective lens do

Produces a magnified image which is magnified again by the eyepiece lens

3

Explain dry mount

Solid specimen viewed into thin slices- sectioning.
Specimen placed on slide and cover slip placed on top

4

Explain wet mount

Specimens suspended in liquid.
Cover slip placed on from an angle

5

Explain squash slides

Wet mount first prepared then lens tissue gently presses down the cover slip

6

Explain smear slides

Edge of slide smears sample, creating a thin even coating on another slide- cover slip placed on top

7

How do you prepare a sample for staining?

It is placed in a slide and air dried. It is then heat fixed by passing through a flame

8

Explain gram stain technique

Separates bacteria into positive and negative gram bacteria

9

What is a counterstain

Safranin dye

10

Explain acid-fast technique

Differentiates species of mycobacterium from other bacteria

11

Define magnification

How many times larger the image Is than the actual size of the object being viewed

12

Define resolution

The ability to distinguish between two separate objects

13

Disadvantages of electron microscopy

Expensive
Controlled environment
Specimens can be damaged and must be dead

14

How do TEM work

Beam of electrons through a specimen are focussed to produce image

15

How do SEM work

Beam of electrons over specimen surface and reflected electrons collected

16

What are artefacts?

Visible structural details caused by processing the specimen and not a feature of the specimen itself.

17

How many components in eukaryotic animal cell?

14

18

What are prokaryotes

Single celled organism with a simple structure of just a single undivided internal area called the cytoplasm.

19

What are eukaryotes?

Make up multicellular organisms like animals, plants and fungi. They contain a membrane bound nucleus and cytoplasm, which contains membrane bound cellular components

20

What is metabolism

Involves both the synthesis and the braking down of molecules

21

Magnification equation

Image size / object size
M = I/A

22

What does staining do

Helps reveal or distinguish different features

23

Light microscopes resolution and magnification

200nm
x1500

24

Electron microscopes resolution and magnification

0.2nm
x500,000

25

m to mm

x1000

26

mm to um

x1000

27

um to nm

x1000

28

nm to pm

x1000