PAG 5: photosynthesis

Cards (8)

state the factors affecting the rate of photosynthesis
light intensity
carbon dioxide concentration
temperature
how is light intensity controlled?
by placing the lamp/light source at different distances from the plant
state a source of error in this practical
bubbles may appear too quickly to be accurately counted
what is the purpose of adding sodium hydrogen carbonate to the beaker containing pondweed?
to provide carbon dioxide for photosynthesis
what is the inverse square law?
light intensity is inversely proportional to the square of distance
light intensity ∝ 1/distance^2
how is the effect of carbon dioxide concentration on the rate of photosynthesis investigated?
keep light intensity and temperature constant
change the concentration of sodium hydrogen carbonate solution
how is the effect of temperature on the rate of photosynthesis investigated?
by immersing the set up in a range of thermostatically-controlled water bath, keeping light intensity and carbon dioxide concentration constant
how is the reliability of this practical improved?
by repeating the practical at each light intensity at least twice and take a mean number of bubbles