lesson 8 required practical 1 microscopes

Question 1

the centre of a microscope has a what

Answer 1

a stage

Question 2

what does the stage do of a microscope

Answer 2

its where we place the microscope slide

Question 3

the stage has clips which does what

Answer 3

it holds the slide in place

Question 4

below the stage there is a what

Answer 4

a lamp

Question 5

light from the lamp passes up through the what

Answer 5

microscope slide

Question 6

some optical microscopes rather than a lamp will have a what beneath the stage

Answer 6

a mirror

Question 7

in some optical microscopes there is a mirror, what does the mirror do (beneath the stage)

Answer 7

it reflects light up through the microscope slide

Question 8

above the stage what do we have

Answer 8

a set of lenses

Question 9

what are the set of lenses called above the stage

Answer 9

objective lenses

Question 10

most microscopes have how many different objective lenses

Answer 10

3

Question 11

the objective lenses usually have a magnification of…

Answer 11

4x
10x
40x

Question 12

what is the eye piece

Answer 12

it is where we look through

Question 12

at the top of the microscope what do we have

Answer 12

the eye piece

Question 13

the eyepiece contains a what

Answer 13

eyepiece lens

Question 14

what is the magnification of the eyepiece lens

Answer 14

10x

Question 15

what are the final parts of the microscopes

Answer 15

the coarse focussing dial

the fine focussing dial

Question 16

what is the first step of using an optical microscope to view a prepared slide
(Step 1)

Answer 16

first we place the slide onto the stage and use the clips to hold the slide in place

Question 17

what do we do after placing the slide on the stage (step 2)

Answer 17

select the lowest power objective lens
(usually 4x)

Question 18

after selecting the lowest power of objective lens, what do we need to do with the objective lens
(step 3)

Answer 18

we need to position the objective lens so it almost touches the microscope slide

Question 19

to do step 3 (position the objective lens so it almost touches the microscope slide), what do we need to do

Answer 19

we slowly turn the coarse focussing dial

Question 20

to adjust the position of objective lens, it’s really important we look at the microscope from where

Answer 20

the side

Question 21

when the objective lens almost touches the slide we then what

Answer 21

stop turning the dial

Question 22

if we look through the eye piece while positioning the objective lens, there is a risk that we what

Answer 22

damage the slide

Question 23

after all the positioning is done what do we do
(step 4)

Answer 23

look down through the eye piece

Question 24

once we look down through the eye piece what do we do (Step 5)

Answer 24

slowly turn the coarse focussing dial

Question 25

slowly turning the coarse focussing dial does what

Answer 25

increases the distance between the objective lens and the slide

Question 26

we slowly turn the coarse focussing dial until what

Answer 26

the cell comes into focus

Question 27

once the cell is in focus, what do we do (step 6)

Answer 27

we use the fine focussing dial to bring the cells to a clear focus

Question 28

how do we calculate the total magnification

Answer 28

we multiply the magnification of the eyepiece lens by the magnification of the objective lens

Question 29

the eyepiece lens has a magnification of what

Answer 29

10x

Question 30

the low power objective lens has a magnification of what

Answer 30

4x

Question 31

multiplying the eye piece lens and the low power objective lens gives us what (10 and 4)

Answer 31

40x

Question 32

once we multiply the eye piece lens and low power objective lens and as it gives us 40x across the 2, we can do what

Answer 32

select a higher power objective lens, eg 10x

Question 33

we need to adjust the what to bring the cell back into focus

Answer 33

fine focussing dial

Question 34

once you see the cell through the microscope what can you do

Answer 34

make a clear labelled drawing of some of the cells

Question 35

using an optical microscope what are the only details we can see from the animal cell

Answer 35

nucleus cytoplasm cell membrane (and maybe mitochondria)

Question 36

in optical microscopes we can definitely not see what

Answer 36

ribosomes

Question 37

if looking at a plant cell, under a light microscope we should be able to see

Answer 37

cytoplasm cell wall nucleus we may also be able to see vacuole chloroplasts

Question 38

on your drawing you should also include what

Answer 38

a magnification scale

Question 39

how do we include a magnification scale in our drawing

Answer 39

place a plastic ruler over the stage

Question 40

in the magnification scale we measure the diameter of the field of view in what

Answer 40

millimetres

Question 41

once we measure the diameter of the field of view of the magnification scale, where do we show this

Answer 41

we show this on our drawing on a scale bar

Question 42

on the scale bar( in measuring the magnification scale) what should you include

Answer 42

the magnification (eg 100x)