Factors Affecting the Growth of Duckweed Introduction============For healthy growth, plants need various substances. Three important mineral ions that can be obtained from the soil only through the roots are nitrates, phosphates and potassium. Nitrates are essential for the production of amino acids and for the "synthesis" of proteins. Phosphates are essential as they play an important role in the reactions involved in photosynthesis and respiration. Potassium is also important as it helps the enzymes involved in photosynthesis and respiration to function. The three main minerals are needed in fairly large quantities, but the other elements are required in much smaller quantities. Iron and magnesium are the most important as they are needed to produce chlorophyll. Without photosynthesis, along with minerals, plant growth would not take place. Photosynthesis produces glucose as "food" and occurs in the leaves of all green plants. Glucose is combined with nitrates (collected from the soil) to produce amino acids, which are then transformed into proteins. The protein amino acid contains carbon, hydrogen, oxygen and nitrogen. Along with potassium, phosphorus and sulfur are the important substances that travel through the roots and along the stem. Photosynthesis requires carbon dioxide, water, light and chlorophyll to continue the process. Without iron and magnesium, chlorophyll could not be produced and therefore the plant would die. Diffusion occurs in the leaves, through the stomata. Membranes allow substances to move in and out as particles from an area of ​​high concentration move to an area of ​​low concentration. This happens in the example of NO4. There... in the center of the paper... and back to the Petri dish. We could do the same experiment but, instead of weighing, we could count the number of leaves. Or we could use a squared sheet of paper to find the surface area by taking a sample of 10 or 20 - this would provide a good range. Another way is to collect 100 duckweeds, dry them in the oven, and then weigh the dry mass of the dead duckweeds. Each week we weighed different samples from the same conditions. However, by removing more, the remaining duckweed has less competition for nutrients. So we could put 100 duckweeds in 6 Petri dishes with the same concentration and it would be more accurate over a 6 week period. Fertilizer increases growth up to a certain point. We could put duckweed at the bottom of a measuring tube, fill it with water, and measure the amount of oxygen every week.