Duckweed Final Lab Write Up PDF

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Duckweed Lab Writeup...

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LAB REPORT - BIOLOGY Duckweed Experiment Final Write Up BOIL 113 Dr. Bologna Destiny Joyner 11/10/2020 Lab Group 6 Introduction: Duckweed is an invasive species because it produces rapidly, causing it to be known as the fastest growing plant. Duckweeds are organisms that can be found beneath the surface of the water (Ghanvzan, 2006). Duckweed are able to absorb nutrients very effectively, which in turn ends up becoming a good source of food for the fish and other animals living there (Hassan and Edwards, 1992). Duckweed are not only the fastest growing plant, but they are also the smallest. They only reach a diameter of 1.5-4.0 mm (Sculthorpe, 1967). Duckweed can be found all across the world and can live within many different kinds of environmental conditions. Duckweed prefers to be in slowmoving waters and around different shelters for protection (McLay, 1974), it also tends to be attracted by enriched environments (Ghanvzan, 2006). The duckweed species are most commonly found within environments that experience mild winters (eFloras.org, 2009). The plants are viewed better when in clumps, which means when they are scattered they are harder to see (Sainty and Jacobs, 1981). Also, since duckweed tends to grow rapidly it mostly stays dense and force what looks like a green blanket that covers the surface of the water. Lastly, the life expectancy of duckweed is 34 days (Harper, 1977). Hypothesis: The experiment investigates the growth of duckweed in response to Coca-Cola and sunlight. The hypothesis that was tested was that sunlight is an essential factor for duckweed growth, and the addition of Coca-Cola will not affect duckweed growth. It was predicted that duckweed exposure to more sunlight and Coca-Cola would have higher population growth. Materials: 1. Six Clear Plastic Cups 2. Duckweed Plants 3. Coca Cola 4. Pipette Procedure: The experiment method was that six separate cups containing the same amount of duckweed were created as the starting sample size of each population. Cups Control A

and Control B were the control cups and placed in a spot with no sunlight and no CocaCola. Cups Treatment 1-A and B were placed in a spot with no sunlight and 1.5 mL of Coca-Cola. Cups Treatment 2-A and B were also placed in a spot with no sunlight and contained 3.0 mL of Coca-Cola. The dependent variable was the population growth in each cup. The independent variable was the amount of sunlight and Coca-Cola each cup received. The population of each cup was counted every Tuesday, Thursday, and Sunday. The duckweed exposed to the most sunlight and 3.0 mL Coca-Cola had the highest amount of population growth. The duckweed that contained 1.5 mL of Coca-Cola had the second-highest amount of population growth. The duckweed that contained no Coca-Cola had the least amount of population growth. Then, when all of the duckweed was placed in a spot with a decent amount of sunlight, the duckweed population growth increased even more. Results: The data reflects the prediction that the duckweed exposed to the most sunlight and the most amount of Coca-Cola out of the six cups had the highest duckweed population. The data supported the hypothesis that sunlight and Coca-Cola are essential for duckweed growth because the cups that were exposed to the least amount of sunlight and Coca-Cola had the lowest duckweed populations. In this experiment, the duckweed grew more when in sunlight and contained more Coca-Cola than no sunlight and no Coca-Cola, which could be due to the different duckweed species preferring different amounts of lights and mixtures.

Raw Data Objective Treatment 1 Treatment 2 Hypothesis Treatment 1 Hypothesis Treatment 2

Destiny Joyner- Control A

Effects of Sunlight and Coca-Cola 1.5 mL of Coca-Cola 3.0 mL of Coca-Cola Negative Growth Positive Growth

Ivana Culic – Control A

Destiny Joyner- Control B

Ivana Culic – Control B

Destiny Joyner- Treatment 1A

Ivana Culic – Treatment 1A

Destiny Joyner- Treatment 1B

Ivana Culic – Treatment 1B

Destiny Joyner- Treatment 2A

Ivana Culic – Treatment 2A

Destiny Joyner- Treatment 2B

Ivana Culic – Treatment 2B

Conclusions: In this experiment, one problem was the absence of sunlight during the first week of the experiment because there wasn’t a place that contained a decent amount of sunlight. During that first week of the experiment, the duckweed continued growing, but it also began to develop a substance that looked like mold, which made the duckweed leaves hard to count. Not only that but after three days, it began to produce a terrible smell that smelled a lot like vomit. In the end, the duckweed had to be moved from its original spot to a place with sunlight. After two days, the duckweed began to smell better, and there was no longer any mold, which made it much easier to count the number of duckweed leaves. Despite these problems, this experiment supported the hypothesis that sunlight is an essential factor in duckweed growth, and Coca-Cola doesn’t affect the population growth of duckweed.

References Ghavzan JN; Gunale VR; Mahaja DM; Shirke DR, 2006. Effects of environemtnal factors on ecology and distribution of aquatic macrophytes. Asian Journal of Plant Sciences, 5(5):871-880, from https://www.cabi.org/isc/abstract/20087205004 Hassan MS; Edwards P, 1992. Evaluation of duckweed (Lemna perpusilla and Spirodela polyrrhiza) as feed for Nile tilapia (Oreochromis niloticus). Aquaculture, 104(3/4):315-326, from https://www.cabi.org/isc/abstract/19921447960 Sculthorpe CD, 1967. The Biology of Aquatic Vascular Plants. London, UK: Edward Arnold Publications Limited, from https://www.cabi.org/isc/datasheet/30243 McLay CL, 1974. The Distribution of Duckweed Lemna Perpusilla in a Small Southern California Lake: An Experimental Approach. Ecology, 55(2):262-276, from https://www.cabi.org/isc/abstract/20087205007 Ghavzan JN; Gunale VR; Mahaja DM; Shirke DR, 2006. Effects of environemtnal factors on ecology and distribution of aquatic macrophytes. Asian Journal of Plant Sciences, 5(5):871-880, from https://www.cabi.org/isc/abstract/20087205004 eFloras.org, 2013. Flora of North America. St Louis, Missouri: Missouri Botanical Garden and Cambridge, Massachusetts: Harvard University Herbaria, Cambridge, MA, from https://www.cabi.org/isc/abstract/20087204118 Sainty GR; Jacobs SWL, 1981. Waterplants of New South Wales. New South Wales, Australia: Water Resources Commission, from https://www.cabi.org/isc/datasheet/30243 Harper JL, 1977. Population Biology of Plants. London, UK: Academic Press, from https://www.cabi.org/isc/abstract/19782321379...