Light Intensity's Effect on Photosynthesis
Aim : To find out how light intensity will affect the rate of
photosynthesis in a piece of Canadian Pondweed.
Prediction : I predict that as I increase the distance between the
light source and the Canadian Pondweed (reducing the light intensity),
the volume of oxygen produced within the time limit (the measure of
the rate of photosynthesis) will decrease. This will happen because as
the light source is moved further away, less light rays will reach the
surface of the Pondweed, shown by this diagram;
Light rays Pondweed Light rays Light source
This will mean that less light (particles or waves) will go through
the clear Cuticle and upper Epidermis and reach the palisade layer.
This means that less light will reach each cell on average, and as
light is needed for photosynthesis to make the water and carbon
dioxide react together (making it a limiting factor) and so less light
means less water and carbon dioxide is reacted together in the time,
therefore there will be a decreased rate of photosynthesis, and less
oxygen produced will be produced as a by-product of the photosynthesis
[IMAGE][IMAGE][IMAGE][IMAGE][IMAGE][IMAGE] I know that photosynthesis
will take place in the plant as there is all the factors needed for
photosynthesis available and present (water, carbon dioxide,
chlorophyll, and light) to the plant and therefore according to the
photosynthesis equation, photosynthesis will occur and the products
will be made. Therefore I know that oxygen will be produced for
collection, during my experiment, because oxygen is stated in the
equation as one of the products made by the plant, in the word and
symbol equations; 6H O + 6CO (sunlight and chlorophyll) C H O + 6O
which means; water + carbon dioxide (sunlight and chlorophyll) Glucose
+ oxygen (oxygen gas = O ).
I also predict that the rate of photosynthesis will increase in direct
proportion to the increasing light intensity up till a certain point
where the rate will decrease and level out. The proportional increase
will happen because of the reason that I have already mentioned above,
and there will be a point where the light intensity will not affect
the rate of photosynthesis because another factor will be limiting the
rate of photosynthesis e.g. level of carbon dioxide or temperature.
Background: Photosynthesis is the process used by plants so that they
can use raw inorganic material i.e. water and carbon dioxide to make
it's own food/biomass (organic) which not only they use, but is also
the ultimate source of energy for animals. A...