One reason for the difference in internal solute concentration is that cacti has a higher concentration of solute because it grows in more dry environments. d) The epidermis of the potato and cactus and the testa of the sunflowers seeds were removed. Suggest a reason for this. e) Predict what the appearance of the cacti tissue would be like at 0.5moldm-3 sucrose solution. f) 1. State how percentage change in mass is calculated. ii. Explain why percentage change in mass is calculated rather than change in mass. g) Explain why temperature has to be controlled in this study. h) State one way in which this experiment could be made more reliable.

d) The epidermis of the potato and cactus and the testa of the sunflower seeds were removed. Suggest a reason for this.<br /><br />The removal of the epidermis of the potato and cactus, as well as the testa of sunflower seeds, is likely done to ensure that the experiment focuses on the internal tissues rather than the outer layers. The epidermis and testa may contain varying concentrations of solutes or other substances that could affect the results. By removing these outer layers, researchers can obtain a more accurate measurement of the internal solute concentration or other properties of interest.<br /><br />e) Predict what the appearance of the cacti tissue would be like at $0.5moldm-3$ sucrose solution.<br /><br />At a $0.5moldm-3$ sucrose solution, the cacti tissue would likely appear swollen and possibly translucent. This is because the lower concentration of sucrose outside the cacti cells compared to the higher internal solute concentration would cause water to move into the cells through osmosis, making them swollen.<br /><br />f)<br />1. State how percentage change in mass is calculated.<br /><br />The percentage change in mass is calculated using the formula:<br /><br />\[<br />\text{Percentage Change in Mass} = \frac{\text{Final Mass} - \text{Initial Mass}}{\text{Initial Mass}} \times 100<br />\]<br /><br />ii. Explain why percentage change in mass is calculated rather than change in mass.<br /><br />The percentage change in mass is calculated rather than the absolute change in mass because it provides a relative measure of the change. This allows for easier comparison between different samples or experiments, regardless of their initial masses. It also helps to normalize the results, making them more interpretable and meaningful in terms of proportions or ratios.<br /><br />g) Explain why temperature has to be controlled in this study.<br /><br />Temperature needs to be controlled in this study because it can affect the rate of osmosis and the solubility of solutes. Variations in temperature can lead to inconsistent results, as changes in temperature may alter the permeability of the cell membranes or the solubility of the solute in the solution. Controlling the temperature ensures that the experimental conditions remain consistent and that the results are comparable.<br /><br />h) State one way in which this experiment could be made more reliable.<br /><br />One way to make this experiment more reliable is to repeat the experiment multiple times and calculate the average result. Repeated trials help to account for any random errors or variations that may occur during the experiment. By averaging the results of multiple trials, the reliability and accuracy of the findings can be improved.