Biology lab 2: Relationship of Organisms (Lab Report Sample)

Biology Lab 2
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Aim: To investigate the relationship of organisms at different trophic levels of a food chain
Abstract
Understanding the food chain relationship between various organisms in an ecosystem is important to ecologists. Consequently, this experiment investigates the relationship between organisms at different trophic levels of a food chain. It is notable that the experiment examined the relationship in different ecosystems. Three main ecosystems, which include the deciduous forest, the hot desert ecosystem, and the grasslands ecosystems, were used in the experiment. The study revealed that every organism is important to a food chain because eliminating any organism from the ecosystem will affect the population of other organisms. The experiment also established that the amount of energy and organisms at every trophic level differs depending on the ecosystem.
Introduction
A food chain is important to an ecosystem because it ensures the organisms have a source of food. The term food chain could be elucidated as a series of organisms that have related feeding habits with the smallest organism being the primary producer of food (Osborne, 2012). It is notable that a food chain contains producers, herbivores, and carnivores. Producers, feed the herbivores, which in turn feed the carnivores. It follows that producers are plants while herbivores and carnivores are animals. Moreover, carnivores could be subdivided into different groups. For instance, carnivores exist in first, second, and third heterotrophs. This implies that the amount of energy in every trophic level is different.
This experiment examines the amount of energy in different trophic levels and ecosystems.
Procedure
The field report was read to understand the relationships between different organisms in the ecosystem. The deciduous forest ecosystem was then selected from the dropdown menu on the top left corner of the virtual lab. Each organism was placed into the correct trophic level in the ecosystem pyramid by clicking the blue circle alongside the organism and dragging it into the pyramid. After dragging all the organisms into the ecosystems pyramid, the check button was clicked to confirm all organisms were in their correct tropic levels. Organisms that were in the wrong trophic levels were adjusted appropriately. The pyramid energy was then clicked to obtain the energy in each tropic level. The pyramid of numbers was also clicked to obtain the number of organisms in each tropic level. The number of organisms in each trophic level were recorded in an excel sheet. The energy conversion for each trophic level was also calculated by calculated by dividing the energy at the higher trophic level by the energy at the lower level to obtain a ratio.
Results
The results of the experiment are tabulated in table 1 below.
Table 1: Results indicating the amount of energy, number of organisms, and the energy conversion efficiency.
Amount of EnergyProducersFirst Order HeterotrophsSecond Order HeterotrophsThird Order HeterotrophsEcosystem 1 (Deciduous Forest Ecosystem)6011623616Ecosystem 2 (Hot Desert Ecosystem)2002120.19Ecosystem 3 (Grassland Ecosystem)2000223192Number of Plants or Animals (Organisms)ProducersFirst Order HeterotrophsSecond Order HeterotrophsThird Order HeterotrophsEcosystem 1 (Deciduous Forest Ecosystem)79964559141850Ecosystem 2 (Hot Desert Ecosystem)2603831585Ecosystem 3 (Type Name Here)5491061887305Energy Conversion EfficiencyProducersFirst Order HeterotrophsSecond Order HeterotrophsThird Order HeterotrophsEcosystem 1 (Deciduous Forest Ecosystem)0.103640.0979133230.0983606560Ecosystem 2 (Hot Desert Ecosystem)0.1050.0952380950.0950Ecosystem 3 (Grassland Ecosystem)0.11150.0852017940.1052631580
The Amount of energy was highest in the deciduous forest ecosystem, followed by the grassland and hot desert ecosystems respectively. The energy also declined progressively at all trophic levels, but the ranking did not change for all ecosystems. The number of organisms was highest in the grassland ecosystem followed by the deciduous and hot desert ecosystems respectively for the first trophic level. However, the ranking changed after the first trophic level where the number of organisms was highest in the deciduous ecosystem, grassland and hot desert ecosystem in the second trophic level. The third trophic level was led by the deciduous ecosystem followed by the hot desert ecosystem and grassland ecosystem respectively. The third order autotroph was led by the deciduous ecosystem while the hot desert ecosystem and grassland ecosystem tied. The energy conversion efficiency for producers was highest in the deciduous forest ecosystem, followed by the grassland and hot desert ecosystems respectively. The second trophic level was led by the deciduous ecosystem followed by the hot desert ecosystem and grassland ecosystem respectively. The third trophic level was highest in the deciduous ecosystem, grassland, and hot desert respectively.
Discussion
The number of organisms and amount of energy in each trophic level indicate that the producers are the main source of food. It is also clear that organisms in a higher trophic level depend on organisms on the lower trophic levels for food because the number of organisms decreases gradually from the producers to the third order heterotrophs for all ecosystems (Osborne, 2012).
Discussion Questions
Suggest reasons why the information represented in the pyramid of numbers of animals of one of the ecosystems you studied may not truly represent that ecosystem.
The expe...