practical: photosynthesis Flashcards
when investigating the rate of photosynthesis what are the possible variables
light intensity, temp, co2, concentration, plant type, surfaces are of a leaf, colour if plant, PH
why do you leave the pondweed 5 minutes after the lamp has been turned on before counting any bubbles
give the pondweed time to acclimate
what pirce of equipment do you use to change the distance of the lamp
ruler
what would you use as a light source
lamp with led bulb
why should you use an ledge when measuring rate of photosynthesis
so it does not heat up and change the temperature of the water
why might sodium hydrogen carbonate be added to water
to ensure that there is excess of carbon dioxide and that this does not become a limiting factor
why are bubbles produced by pondweed during the photosynthesis experiment
number of bubbles produced in a given time
what is the dependent variable when investigating photosynthesis
oxygen is a product of photosynthesis and so when the pondweed photosynthesises it makes bubbles of the gas that we can count
why us it important to use a thermometer when investigating the rate of photosynthesis
jt is used to measure the temperature, to check the temperature isnt changing. this is important because the temperature needs to be controlled
how can we cange the light intensity when investigating how light intensity affects the rate of photosynthesis
change the distance the lamp is from the plant
how can the temperature be controlled in the experiment
add the pondweed sample to a beaker of water, this helps maintain the temperature
why is it better to count the number of bubbles every minute for 3 minutes rather than just count bubbles for 3 minutes
you can see outliers and so improves reliability
what two measurements need to be taken when investigating the rate of photosynthesis
the number of bubbles produced jn a certain time
in an alternative method us to out discs of pondweed in a beaker and measure the time to rise to the surface, why would the disc rise to the surface
they have made oxygen, which causes them to float to the surface
