Experiments

Question 1

Starch

Answer 1

Iodine solution - brown to blue black

Question 2

Reducing Sugar

Answer 2

Benedictus solution + heat = blue to brick red

Question 3

Protein

Answer 3

Biuret Regent = Blue to lilac

Question 4

Fat

Answer 4

Permenant translucent stain on brown paper bag

Question 5

Examine plant cell

Answer 5

Remove very thing piece of onion
place tissue on a slide
add few drops of iodine to stain cell
Blot of surplus stain
Add a drop of water
Add cover slip at 45 degree angle - eliminates air bubbles
examine cells under low and high power magnification

Question 6

Examine animal cell

Answer 6

Scrape inside of mouth with cotton bud. Gently smear sample on slide
Add methylene blue ( nucleus stains a deep blue)
Blot off surplus stain
Add a drop of water
Add a cover slip at 45 degree angle to eliminate air bubbles
examine cells under low and high concentration

Question 7

Influence of light intensity on the rate of photosynthesis

Answer 7

Cut the stem of a piece pond wood at an angle, place it in a test tube, cut end up. Prevent elodea from floating p by attaching paper clip to it

Add 0.1% sodium bicarbonate to the test tube.
Place test tube in water at 25 degrees
Place bench lamp 1m from elodea and leave for 5 minutes
Count number of bubbles produced in 1 minute. Repeat 3 times and find average
Repeat procedure with lamp at 80cm,60cm…
Graph results

Question 8

Prepare and examine a dicot stem

Answer 8

Use wet blade to cut herbaceous stem such as celery. Woody stem to difficult to cut
Store the sections in petri dishes to prevent dehydration
Transfer section to a microscope slide using a paintbrush
Stain with iodine blot off excess stain. add a drop of water and a coverslip at an angle
Observe the dermal, ground and vascular tissue under low and high power magnification