photosynthesis practicals

Question 1

What is the method to find out if a plant produces oxygen during photosynthesis ?

Answer 1

1 - add a spatula of soium hygrogen carbonate into a beaker of water (source of CO2)
2 - place some elodea (pondweed) into the water
3 - cover the elodea with a upturned funnel
4 - place a test tube of water over the funnel
5 - leave it near a light source for at least 2 days

Question 2

What gas does a plant produce when it photosynthesises ?

Answer 2

Oxygen

Question 3

What will soda lime do the CO2 concentration in the air ?

Answer 3

It will absorb the co2, decreasing the concentration.

Question 4

What will sodium hydrogen carbonate do to the concentration of co2 in the air ?

Answer 4

It gives off co2, so it will increase the concentration.

Question 5

what is the method to find out if a plant need light to photosynthesise ?

Answer 5

1 - attach a piece of tinfoil to a leaf
2 - place in a well lit place
3 - put it in boiling water
4 - put plant into bottom of a boiling tube
5 - add ethanol
6 - put the boiling tube into the boiling water
7 - put leaf on a white tile and iodine
8 - if it turns blue/black starch is present

Question 6

What is the method to measure the rate of photosynthesis using elodea ?

Answer 6

1 - put elodea into a boiling tube of water
2 - add a spatula of sodium hydrogen carbonate
3 - place this boiling tube into a beaker of warm water
4 - shine a light on it
5 -count how many bubbles are given off in one minute