2019 Year 12 IB Extended Essays

Temperature of plants

The temperature of the plant will be kept constant by growing the plants indoors by maintaining a temperature of 24˚C through the use of air-conditioning

This will ensure that none of the plants are exposed to higher temperatures (direct interaction with sunlight) than others as if this occurred, the enzymes within the plants that were placed in a cooler environment will function slowly and The size of the cups will need to remain constant as if the diameter of one cup was larger, the rate of evaporation would be higher which would mean that the plant in that cup will be exposed to a higher concentration of salt for a longer period of time as all the solutions are watered with de-ionised water at the same time This will ensure that the concentration of the detergent in the water isn’t affected by the evaporation of the water and is only changing due to being either utilised by or immobilised on to the cells of the plant the rate at which the plant immobilises contaminants

Cup size

All the cups in which the plants will be grown will have a capacity of 550ml and will be the same shape and size.

Water Level

A small line will be drawn two centimetres below the lip of the pot to ensure that the water level always remains constant

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