Pond Weed Practical

Question 1

Pondweed practical for rate of photosynthesis

Answer 1

• the rate of photosynthesis can be measured by the volume of oxygen produced by pondweed
• light source(white) is placed at a specific distance from the pondweed use a ruler
• pondweed is placed in tube of water with capillary tube and syringe attached
• pondweed left to photosynthesis for a set time
• oxygen collects in capillary tube and syringe is used to draw gas bubble in the tube alongside the ruler and length is calculated(proportional to volume of oxygen produced)

Question 2

Control variables

Answer 2

Temperature

Time

Question 3

Reproducibility

Answer 3

Repeated twice at the same distance so mean is calculated

Then the whole experiment is repeated with the light source at different distances from pondweed

Question 4

How can it be altered to measure effect of temperature or co2

Answer 4

Put in water bath at set temp
Or
Measure amount of sodium
hydrogen carbonate can be dissolved in the water(gives of co2)

Question 5

Alternate way to measure light effect is

Answer 5

Count the bubbles of oxygen in a set amount of time