The effects of Baking Soda (Sodium Bicarbonate) on Lemna minor

Abstract

This experiment was done to determine how adding baking soda to Lemna minor's environment would affect its growth and survival. I hypothesized that adding a small amount of baking soda to the water would improve Lemna growth rates. However, the results of this experiment indicated my predictions were incorrect and the change in the pH of the water caused by the addition of baking soda was actually extremely detrimental to the Lemna. By the end of our experiment only the Lemna in the control group continued to reproduce, while all but one of the independent variables died completely and all were unable to produce new Lemna.

The overall objective of this lab experiment was to determine how different amounts of a certain chemical would affect the growth and survival of a population of Lemna. Lemna is a free-floating tiny aquatic freshwater plant. It is most commonly known by the name lesser duckweed. The reason it got the name duckweed is that it is a good source of food for waterfowl and other aquatic organisms such as fish and frogs. They do not have true leaves, but instead have leaf-like structures that are known as fronds.

Lemna has a single root that hangs below the surface of the water, allowing the Lemna plants receive their nutrients from the water rather than soil. Lemna grows very quickly and can be manipulated easily in a laboratory setting, which made it an ideal choice for this experiment, which took place over the course of five weeks. Lemna requires a lot of sunlight to grow and does not do well in shady areas. It also does not tolerate cold weather.