Discussion The highest concentration had the highest population at the end of the experiment, while the lowest concentration had the lowest population at the end of the experiment. 10%, 15% and 20% had very close averages throughout the experiment. The last day had a big influence on all of the graphs. Most of the experiments either went high up or low down on the last day. When you compare the various concentrations of K PO to the control they all grew, many of them exponentially. Research from "Duckweed Summary"ÃÂ showed that Duckweed grows under most conditions. The best way we could make this experiment more accurate it would be to improve it by eliminating the possible sources of error. The possible sources of error are, miscounting, mistakes in K PO and other organisms living in the petri dish besides duckweed.
In culture solution deficient of calcium ions , areas between leaf veins become yellow are observed on second day. The leaves have distorted shape. Growth of the leaves is stunted and the growing points die back too as lack of calcium affects plant cell growth and enzymatic reactions. This is shown with no more living Lemna plants from Day 4 onwards as all the leaves turn white and disintegrate. This happens because calcium ion is needed for the formation of cell wall during cell division. Lacking of calcium ion will cause no cell division occur as calcium pectate cannot be formed. Permeability of the cell is also affected. Lacking of calcium causes the cell sap and the cytosol diffuse out of the cell. This will cause the death of cells.