Biology Core Practicals: 1 - Microscopes

Question 1

Where is the stage?

Answer 1

At the centre of the microscope

Question 2

What is the purpose of the stage?

Answer 2

It is where the microscope slide is placed

Question 3

What holds the microscope slide in place?

Answer 3

The clips either side

Question 4

What is below the stage?

Answer 4

A lamp

Question 5

What is the purpose of the lamp?

Answer 5

The light from the lamp passes up through the microscope slide to provide light shining through the coverslip and object in it

Question 6

Instead of a lamp what do other microscopes have?

Answer 6

A mirror

Question 7

What is the usage of a mirror?

Answer 7

It reflects the light up through the microscope slide

Question 8

What is above the stage?

Answer 8

Lenses, objective lenses

Question 9

How many objective lenses are there?

Answer 9

Three

Question 10

Usually, what is the magnification of each three?

Answer 10

4x,10x,40x

Question 11

What is at the top of the microscope?

Answer 11

The eyepiece

Question 12

What does the eyepiece contain?

Answer 12

The eyepiece lens

Question 13

Usually, what is the magnification of the eyepiece lens?

Answer 13

Magnification of 10x

Question 14

Name the two dials?

Answer 14

Course focusing dial
Fine focusing dial

Question 15

Where do you put the cells?

Answer 15

On a microscope slide

Question 16

For plant cell what you add to the cell?

Answer 16

A drop of water or iodine, a chemical stain

Question 17

Once your cell and stain is on the slide, what is next?

Answer 17

Lower your coverslip, gently to prevent trapping air bubble

Question 18

For animal cells, how do you place them on the slide?

Answer 18

Using cotton bud, rub them on the inside of your cheek/animal

Question 19

Once the cotton bud contains the cell DNA, what is next?

Answer 19

Smear the cotton bud onto the slide

Question 20

What do you do once the slide contains cell/DNA from an animal cell?

Answer 20

You must add a drop of methylene blue, chemical stain

Question 21

After the cell/DNA is on the slide, what is next?

Answer 21

Lower the coverslip, gently to prevent the trapping of air bubble

Question 22

Why are chemical stains used?

Answer 22

To make cell parts more obvious

Question 23

Why is a thin layer of a plant cell used under a microscope and not a thick one?

Answer 23

This is to make it easier to see the cell

Question 24

When the slide is prepared, what is next?

Answer 24

Place the slide onto the stage and use the clips to hold it in place

Question 25

Once the slide is in place, what is next?

Answer 25

You must select the lowest power objective lens and position is almost touching the microscope, usually 4x

Question 26

How do you position the lens almost touching the microscope slide?

Answer 26

Turn the coarse focusing dial, looking from side on of the microscope

Question 27

When do we stop turning the dial?

Answer 27

Once the objective lens is almost touching the slide

Question 28

Why do we look at the microscope from the side?

Answer 28

As there is a risk damaging the slide if we look through the eyepiece lens

Question 29

Once it is set up, what is next?

Answer 29

We look down the eyepiece lens

Question 30

Once we look down the eyepiece lens, what is next?

Answer 30

Turn the coarse focusing dial

Question 31

Why do we turn the coarse focusing dial?

Answer 31

BRINGS THE CELL INTO FOCUS, decreasing the distance between the objective lens and the slide

Question 32

How are the cells brought into a CLEAR focus?

Answer 32

Use the fine focusing dial

Question 33

How do you calculate the total magnification?

Answer 33

Total Magnification = Magnification of eyepiece X Magnification of objective lens

Question 34

If the eyepiece lens has a magnification of 10x and the low-power objective lens has a magnification of 4x What is the total magnification?

Answer 34

40x

Question 35

After using the lower power objective lens, what can we now do?

Answer 35

Select the higher power objective lens

Question 36

How do you include a magnification scale?

Answer 36

Place a clear plastic ruler over the stage, measure the diameter of the field view in mm

Question 37

What do you do when you are showing a drawing of magnification?

Answer 37

Use a scale bar

Question 38

What do you do when you are showing a drawing of magnification?

Answer 38

Show the magnification you are using