My reasons for believing my results are reliable & accurate are
firstly, they agree with the theory behind the rate of photosynthesis
when light intensity is increased, secondly the result which I gained
compared accurately to my prediction, which was well thought out
before it was made, and finally the results I gained for my final
experiment differed so much to the results of my preliminary procedure
which was very inaccurate.
Even though we are measuring whether the
rate of photosynthesis is affected by different levels of exposure to
CO2, It would only be a fair test if the different range of levels can
clearly be measured, which they cannot be clearly measured if the test
is conducted with the same water, even though the levels of CO2 would
Factors that affect Photosynthesis are: ..
My reason for believing this
is that as mentioned previously, light is one of the limiting factors
required for photosynthesis, and by lowering the amount of light
available to the plant, I will be decreasing the rate at which the
process of photosynthesis takes place in the plant.
Three factors can limit the speed of photosynthesis ..
To summarise: For the rate of photosynthesis to increase beyond a
certain point, it cannot be relied on for just 1 of the 4 limiting
factors to increase, after a certain point ALL must increase for the
rate to increase.
If it gets too cold, the rate of photosynthesis will decrease.
The reason for this being that the other 3 "limiting
factors" (CO2, water & chlorophyll) are required in a higher quantity
too, for photosynthesis to continue increasing in rate.
Physiological factors that affect photosynthetic rates
At a point (which was not
displayed on my graph, so logically this point is higher than the
highest light intensity I provided the pond weed with) the rate of
photosynthesis will stay steady , it will increase no further (see
What are some of the factors that affect photosynthesis
20 degrees centigrade is the
recommended temperature for photosynthesis, and yet we conducted out
experiment with the water around 25-27 degrees C, as I found that 20
degrees was a little low.
External Factors Affecting Photosynthesis
The most probable explanation for the results I gained; as mentioned
previously in my introduction, as light is one of the factors required
in order for photosynthesis to take place, as the intensity of the
light is increased, photosynthesis is able to take place at a higher