Essay On Seed Germination
The research question: What is the effect of changing the pH of the soil on the germination and growth of mustard peas?
Hypothesis: The greatest number of peas will germinate and will grow the most when the pH is 5 or 7.
Theory: Enzymes play a vital role in the cells of plants (especially when growing) and enzymes work best when at their optimum pH value. Moreover, all chemical reactions have an optimum pH at which they work best (Howard and Loomis, no date). Generally the enzymes in plants work best at a pH of around 5-7. For examples, lipases work best at a pH of between 4-7 (Barros, Fleur and Macedo, 2010). Furthermore, celluloses, which break down specific carbohydrates, have an optimum pH of between 4-5. This leads me to expect that the greatest number of seeds will germinate when the pH is slightly below neutral (7) (SERVA Electrophoresis GmbH, no date). …show more content…
To keep the water levels the same 5cm3 of water will be added to the soil every day. Soil of the same type and water level will be used so that the water content of the soil is the same. The humidity of the room will be kept the same for all experiments so that water levels in the air are also the same. Mineral, vitamin and ion content of the soil: This needs to be kept the same as mineral, vitamin and ion levels in the soil could have an effect on growth and germination. This is hard to control with a high degree of accuracy but if the same type of soil is used and nothing is added then the mineral, vitamin and ion content of the soil should remain relatively similar. Time: The time that each seed is left to germinate and grow needs to be the same so that it is regarded as a fair test. Conducting each experiment for a week will ensure that the time, for which each experiment is left, is the