ib biology ia
How does light intensity affect the rate of photosynthesis?
Does the amount of light intensity increase the rate of photosynthesis in a pondweed?
Design aspect 1
Introduction
My investigation will be centered on measuring the rate of photosynthesis and whether or not light intensity will affect it. The formula of photosynthesis is Carbon dioxide + water oxygen + glucose with the arrow referring to light energy as a means to convert the CO2 and H2O into oxygen and glucose. Logically, one would assume that with a higher light intensity, a plant would gain more energy and therefore continue the process of photosynthesis at a more rapid rate.
I will conduct the experiment in a room with constant temperature as to minimise the chance of other factors that might affect the rate of photosynthesis of the pondweed (Cabomba or Elodea). I will also limit the chance of a change in concentration in the water that the pondweed will be set in. Furthermore, the result of the experiment will be based solely on the amount of bubbles I see, or what rate of oxygen is being made by the plant, through its production of bubbles.
Hypotheses
Null hypothesis: That the rate of photosynthesis would increase with increasing light intensity
Alternative hypothesis: That the rate of photosynthesis would hit a maximum on a certain light intensity and plateau with increasing light intensity
Dependent variables - x
Rate of photosynthesis (measured by amount of bubbles coming out of the stalk of the pondweed) – the uncertainty of this however, is that it is dependent on the eyes of the conductor of the investigation
Independent variables - y
Time period (1 minute)
Temperature of water/ room (25ºC – 27ºC depending on the room temperature at the time)
Light intensity
The distance in which the lamp is moved with each minute of results (10 cm)
Factors to control
The light intensity of the room, must be kept the same – conduct experiment in the same room each time
Does the amount of light intensity increase the rate of photosynthesis in a pondweed?
Design aspect 1
Introduction
My investigation will be centered on measuring the rate of photosynthesis and whether or not light intensity will affect it. The formula of photosynthesis is Carbon dioxide + water oxygen + glucose with the arrow referring to light energy as a means to convert the CO2 and H2O into oxygen and glucose. Logically, one would assume that with a higher light intensity, a plant would gain more energy and therefore continue the process of photosynthesis at a more rapid rate.
I will conduct the experiment in a room with constant temperature as to minimise the chance of other factors that might affect the rate of photosynthesis of the pondweed (Cabomba or Elodea). I will also limit the chance of a change in concentration in the water that the pondweed will be set in. Furthermore, the result of the experiment will be based solely on the amount of bubbles I see, or what rate of oxygen is being made by the plant, through its production of bubbles.
Hypotheses
Null hypothesis: That the rate of photosynthesis would increase with increasing light intensity
Alternative hypothesis: That the rate of photosynthesis would hit a maximum on a certain light intensity and plateau with increasing light intensity
Dependent variables - x
Rate of photosynthesis (measured by amount of bubbles coming out of the stalk of the pondweed) – the uncertainty of this however, is that it is dependent on the eyes of the conductor of the investigation
Independent variables - y
Time period (1 minute)
Temperature of water/ room (25ºC – 27ºC depending on the room temperature at the time)
Light intensity
The distance in which the lamp is moved with each minute of results (10 cm)
Factors to control
The light intensity of the room, must be kept the same – conduct experiment in the same room each time