Tim Hodgson 11M
Introduction:
All living green plants photosynthesise. In photosynthesis, carbon dioxide, water and light are absorbed and used to form glucose for the plant and oxygen as a by-product. As with all reactions, the rate can be changed by altering a number of factors. In photosynthesis, the most substantial variables which affect the rate are temperature, carbon dioxide concentration and light intensity.
This is the premise of this experiment - investigating the limiting factors in photosynthesis. Due to restrictions in the environment, it would not be viable to alter the carbon dioxide concentration in the air in the classroom and it would be near impossible to achieve a suitable degree of accuracy if temperature was the independent variable. Therefore, light intensity had to be chosen as the factor to be investigated. The plant on which the theory and prediction will be tested will be Canadian pondweed.
Aim:
The aim of this experiment is to investigate how light intensity affects the rate of photosynthesis in Canadian pondweed.
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Teacher Reviews
Here's what a teacher thought of this essay
Overall, this is a fairly competent piece of work which describes an investigation into the effect of light intensity on the rate of photosynthesis. The conclusion and evaluation have been omitted but the introduction, method and results sections are sufficiently detailed to warrant a C grade at GCSE. To gain the higher grades, a number of improvements would have to be made. These include: [1] A more detailed introduction based on previous work carried out by other scientists on limiting factors. There is no shortage of this online. [2] A clear hypothesis is required to form the basis of the investigation. [3] A more detailed discussion of variables and the way in which they were controlled. Key variables such as temperature and carbon dioxide were given rather scant mention. Overall, 3 stars.
