potometers

Question 1

what is a potometer

Answer 1

a device used to measure the rate of water uptake by a plant

Question 2

why do you put oil on the water

Answer 2

to prevent water evapourating form the measuring cylinder directly

Question 3

why is it better to measure mass change of system that water change

Answer 3

gives more accurate results as some water is used in photosythesis so not all water taken up is lost through transpiration if we only looked at water change we aren’t taking into account the water in the leaves for photosythesis

Question 4

what were the results in day/light

Answer 4

more transpiration occoured when placed in light as light provides energy for evapouration making water molecules move faster and stomata open in light to allow CO2 in for photosythesis and open stomata means more water can evapourate

less in dark as stomata close because no light means no photosythesis so not C02 needed and less heat so evaporation is slower