2.1.1

Question 1

Define magnification

Answer 1

how much bigger a sample appears to be under a microscope than it is in real life

Question 2

Define resolution

Answer 2

The ability to distinguish between two points (level of detail)

Question 3

Equation for total magnification

Answer 3

objective mag x eyepiece mag

Question 4

What magnification is a light microscope limited to?

Answer 4

1500x

Question 5

Difference between how a light microscope works and how an electron microscope works

Answer 5

Light microscope exposes specimen to light, electron microscope exposes it to electrons

Question 6

What are the two types of electron micropscope?

Answer 6

• Scanning (SEM)
• Transmission (TEM)

Question 7

Why can electron microscopes have a greater resolution than light microscopes?

Answer 7

Electrons have a shorter wavelength than light

Question 8

Definition of “plane of view”

Answer 8

the side you see

Question 9

How are specimens prepared in a scanning electron microscope?

Answer 9

Specimens coated with a layer of metal

Question 10

Why are specimens covered in a layer of metal pre-viewing?(Scanning EM)

Answer 10

To improve conductivity and contrast

Question 11

Why must specimens be dead to be viewed under an electron microscope?

Answer 11

Specimens are put in vacuum where they’d die anyway

Question 12

Do SEMs produce a 2d or a 3d image?

Answer 12

3D

Question 13

SEMs allow ______ cells/organisms to be scanned

Answer 13

whole

Question 14

How is a TEM specimen prepared?

Answer 14

Very thinly sliced and coated in a heavy metal

Question 15

Does a TEM produce a 3d or a 2d image?

Answer 15

2d

Question 16

How does a TEM work on a prepared specimen?

Answer 16

Fires electrons which don’t pass through the heavily stained parts.
Electrons that pass through are focused by electromagnets onto a fluorescent screen

Question 17

Name the 4 slide preparation methods

Answer 17

Dry Mount
Wet Mount
Squash slide
Smear

Question 18

What are dry mount slides useful to look at

Answer 18

whole, solid specimens such as hair, insect and pollen

Question 19

How are dry mount slides prepared?

Answer 19

specimen placed on center of slide then cover slip is placed over sample

Question 20

What are wet mount slides useful to look at?

Answer 20

Living or wet samples such as pond water or bacteria

Question 21

How is a wet mount slide prepared?

Answer 21

small drop of liquid placed on slide
place specimen on top
slowly tilt and lower cover slip, to ensure no bubbles

Question 22

What are squash slides useful to look at?

Answer 22

soft samples such as plant roots or onion

Question 23

How is a squash slide prepared?

Answer 23

wet mount prepared first
lens tissue used to gently press down on cover slip

Question 24

What are smear slides useful to look at?

Answer 24

blood samples

Question 25

how is a smear slide prepared?

Answer 25

edge of slide used to smear the sample (slide at 45 angle), creating an even, thin layer cover slip placed on sample

Question 26

What is an artefact?

Answer 26

A visible structural detail not a feature of the object usually obtained during the making of the slide

Question 27

Why is staining slides useful?

Answer 27

Allows us to see transparent/hard to see cells

Question 28

What is differential staining?

Answer 28

Using stains which bind to specific cell structures, meaning each structure can be stained differently and easily identified

Question 29

3 examples of differential stains

Answer 29

- methylene blue: stains nuclear material - iodine: stains starch (cell walls) - gram staining: stains bacteria cell walls

Question 30

How can gram staining help classify bacteria?

Answer 30

It is either gram negative or gram positive. bacteria can be further classified using other stains

Question 31

Magnification using sizes equation

Answer 31

Magnification = image size / actual size

Question 32

What is an eye piece graticule?

Answer 32

A fine scale that fits inside the eyepiece lens. Units are arbitrary

Question 33

What is a stage micrometer?

Answer 33

A scale fitted onto a coverslip, where the units are known

Question 34

Is the scale on a stage micrometer known or unknown?

Answer 34

Known

Question 35

How can we find the value for the units of an eyepiece graticule using a stage micrometer?

Answer 35

Align the two scales and use the known unit to work out the unknown

Question 36

What is cytosol?

Answer 36

The liquid component of cytoplasm

Question 37

What are the 4 parts of the nucleus?

Answer 37

- nuclear envelope - nuclear pore - chromatin - nucleolus

Question 38

What are chromatin?

Answer 38

substance consisting of DNA and proteins

Question 39

What are nuclear envelopes?

Answer 39

double membranes around edge of nucleus

Question 40

What is the nucleolus?

Answer 40

Dense regions of DNA, RNA and proteins where ribosomes are synthesized

Question 41

What is the function of a nucleus?

Answer 41

Controls cell functions Controls gene expression, protein synthesis and storing DNA

Question 42

How does the nucleus control cell functions?

Answer 42

DNA transcription

Question 43

The mitochondria has _ membranes

Answer 43

2, an inner and an outer membrane

Question 44

How is a mitochondrion's inner membrane structured?

Answer 44

Folded with high surface area

Question 45

What is a mitochondrion's inner membrane called?

Answer 45

Cristae

Question 46

Why does mitochondria have their own DNA?

Answer 46

To synthesize specific enzymes

Question 47

What is the function of mitochondria?

Answer 47

Aerobic respiration

Question 48

Where does anaerobic respiration occur?

Answer 48

Cytoplasm

Question 49

What is a permanent cell vacuole's membrane called?

Answer 49

tonoplast

Question 50

What does the permanent cell vacuole contain?

Answer 50

Cell Sap

Question 51

What are the functions of a permanent cell vacuole?

Answer 51

- Stores cell sap - maintains osmotic pressure within the cell

Question 52

Chloroplasts have a ______ membrane

Answer 52

double

Question 53

What are stacks of thylakoids in chloroplasts called?

Answer 53

Grana

Question 54

What are the stoma sacs in chloroplasts called?

Answer 54

Thylakoids

Question 55

How are grana linked together in chloroplasts?

Answer 55

By pieces of membrane called lamellae

Question 56

What is the function of chloroplasts?

Answer 56

Photosynthesis

Question 57

What is the Golgi complex made up of?

Answer 57

Golgi apparatus and small vesicles

Question 58

What is the structure of the Golgi complex?

Answer 58

Membrane - bound, fluid filled, channel like structure

Question 59

What are vesicles?

Answer 59

Detached, fluid filled pockets

Question 60

What is the purpose of the Golgi complex?

Answer 60

- Processes and packages proteins and lipids e.g glycoproteins - Proteins and lipids stored in vesicles can be transported out through the cell membrane

Question 61

What is the lysosome?

Answer 61

A type of vesicle containing enzymes such as lysozyme

Question 62

What is the function of the lysosome?

Answer 62

To digest/break down invading cells, old parts of cells and complex biomolecules

Question 63

What is the rough endoplasmic reticulum?

Answer 63

A network of channel like structures filled with fluid

Question 64

What is the difference between Rough ER and smooth ER

Answer 64

Rough has ribosomes along the surface

Question 65

Why does the rough ER have a large surface area and ribosomes along the surface?

Answer 65

For protein synthesis

Question 66

What is the purpose of the rough endoplasmic reticulum

Answer 66

protein synthesis