Introduction:
Photosynthesis is an essential process plants use to convert light energy from the sun into chemical energy, released as glucose. Some of the limiting factors of photosynthesis include temperature, amount of light, the concentration of carbon dioxide, availability of water and the concentration of chlorophyll. Fig.1- The word and symbol equations for photosynthesis.
The aim of the practical is to model the rate of photosynthesis by measuring the time it takes for leaf discs to rise to the surface of a 6% sodium bicarbonate solution. Small discs will be cut out from ivy leaves and by placing them in a syringe, the air will be removed from the spongy mesophyll cells which will make the discs less dense than …show more content…
4- The table shows the raw data for average results of the whole class. The values have not been rounded. Fig. 5- This graph shows that the rate of photosynthesis decreases as more sheets of paper filtered the light.
The scatter of the points on figure 5 indicate that some errors occurred during the practical. The data is precise as the points lie on the line of best fit, however, it is not accurate because the leaves do not rise at the same time. Instead, they rose at different times. The values for the time was not rounded to prevent imprecision of the data, because if the data was rounded to the nearest decimal place, then the data would become higher or lower than the actual value. The trends shown in both graph is that the leaves rise gradually as the line of best fit does not occur in a horizontal or diagonal straight line.
420 seconds is an outlier, as it did not fit within the line of best fit. There were two values of 420 seconds but, as suggested by figure 3, the value furthest away from the line of best fit is the only outlier. The other value would not be an outlier as it was closest to 444 seconds and lies close to the line of best fit.