Required Practicals

Question 1

Microscopes layout

Answer 1

1. Stage, centre of microscope.
2. Stage has clips to hold slide in place.
3. Lamp/ mirror below the Stage.
4. Objective lens above the stage.
5. Eyepiece where we look through.
6. Coarse focus wheel.
7. Fine focus wheel.

Question 2

What does the coarse focus wheel do?

Answer 2

Increase the distance between the objective lens and the slide.

Question 3

What does the fine focus wheel do?

Answer 3

Brings clear focus to the image.

Question 4

How to calculate magnification??

Answer 4

I Magnification=
A M image size÷
actually size

Question 5

Photosynthesis required practical

Answer 5

Fill a test tube with sodium hydrogen carbonate solution and place it on a ruler. Place some pondweed in the tube. Have an LED light on at one end of the ruler and turn it on in timed intervals to see the bubbles form for the mean number of bubbles.

Question 6

What is the inverse square law?

Answer 6

If we double the distance, then the number of bubbles per minute falls by a factor of four.

Question 7

Food tests

Answer 7

Starch- iodine orange to blue-black.
Sugars- benedicts, place in hot water green yellow brick red.
Protein- burette blur to lilac.
Lipids- ethanol, shake cloudy white.
FILTER ALL BUT LIPIDS BEFORE ADDING CHEMICALS