104 DBQ
1a) Boiling and cooling the water before the experiment is necessary as this process removes carbon dioxide and other dissolved gases from the water. Without this procedure, the results could become inaccurate as there is carbon dioxide that is not taken into account which effects the rate of photosynthesis.
1b) Maintaining the temperature of the water at 25 degrees (room temperature) is vital because the rate of photosynthesis can differ according to temperature. As a result fluctuations of temperatures during this experiment will produce inaccurate data. In addition, ‘brightly illuminating’ (light source) the water, is an essential component of photosynthesis.
1c) Counting bubbles is already an inaccurate method of collecting data, thus by repeating counts the data is more reliable and accurate.
2)
3) Taking into account the sizes of each bubble could produce further accurate data.
Question 2 on p. 22 (SG)
ai) Inverse relationship
aii) Inverse relationship
b) Temperature
ci) When there is a low level of light intensity and low temperature (less enzymic action) , a low rate of photosynthesis occurs, thus carbon dioxide is not accumulated, raising levels of carbon dioxide concentration.
cii) When there are high levels of light intensity, slightly higher temperatures, a higher rate of photosynthesis occurs, accumulating most of the carbon dioxide, decreasing levels in carbon dioxide concentration.
Posted in: SL1 Biology
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Posted on January 8, 2013
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