User:Nicholas Carey/Notebook/Biology 210 at AU

1/28/2015- NC

A Study of the Protozoa and Algae Present in Transect #5 Intro- Eukaryotes and Prokaryotes form the two main divisions of life forms. Eukaryotes are cells that contain nuclei and can range from single celled to multicellular organisms. Single celled Eukaryotes generally fall into one of two groups: photosynthetic algae or heterotrophic protozoa. This experiment attempts to identify some of the microscopic eukaryotes present in our ecosystem and the niches they occupy.

Materials and Methods- Samples were taken from two distinct niches of the culture, one from the top layer and the other from the bottom sediment. Then each distinct sample was put on a slide with proto-slow for observation. From each of the two slides three different species of organism were identified for a total of six different organisms. These organism were identified using a dichotomous key which was provided in class. After this the entire culture was shaken up to create uniform distribution.100 uLs of this solution was added to 10 mLs of broth. Then 100 uLs of this second solution was added to another 10 mLs of broth. This process was repeated two more times resulting in 4 solutions of varying concentration. The following solutions had concentrations of 1:100, 1:10,000, 1:1,000,000, and 1:100,000,000. 100 uLs of each solution was then platted onto labelled normal agar plates, and another 100 uLs of each solution was platted onto labelled tetracycline agar plates. Plates were inoculated using a glass spreader dipped in ethanol and passed through flame. And then incubated for next week’s lab.

Data/Observations- The culture smelled of dirt, slightly musky in nature. The aromawas not offensive or pungent. There appeared to be a mold on top which was primarily brown with small white specs dotted throughout. All the organisms observed were motile protozoa that utilized cilia to move, as a result they do not photosynthesize.

Conclusions- Euplotes are capable of reproduction, consist of a cell, respond to their environment, engage in anabolic and catabolic reactions, grow, and regulate homeostasis. If the Hay Infusion Culture was left for two more months the amount of anaerobic bacteria would likely increase as oxygen becomes more scarce in the jar. Also, the amount of bacteria decomposing the organic matter would likely decrease as it was used up. The selective pressures that could affect the community would be interactions between species. Some species release toxins to disrupt other species in order to promote their own growth. These different fluctuations of biotic and abiotic factors create unique niches within the culture which allow for certain species to flourish in some areas over others. For example those organisms by plant matter are likely to be decomposers of the plant matter and likely anaerobic in nature since the plants release CO2 as they decompose, amongst toxic substances like ammonia.

References- Bentley, Meg. 2015. A Laboratory Manual to Accompany: General Biology II. American University: Washington, DC. Pg.16-17

1/23/2015- NC

An intro to Biological Life at AU- Assignment of Transect

Intro- Ecology is the study of how different factors within an environment interact (Bentley, 2015). In order to better understand these interactions and the diversity of life, a transect will be studied. A transect is a small patch of land, that works as a manageable ecosystem to study rather than studying a huge area. The purpose of this experiment is to familiarize each group with their transect. This familiarization will likely be useful in the upcoming experiment centered on each group's transect.

Materials and Methods- The class was broken up into groups and each group was lead to their respective transect. Each group also was given a container for a soil sample. Each group member had to draw and label the transect, being sure to account for all abiotic and biotic environmental factors. After the transect was properly diagrammed, a sample was taken from the soil that best represented the make up of the transect. This sample of soil was then used to make a Hay Infusion Culture for another experiment. 10 to 12 grams of the soil was placed in a labelled jar with 500 mLs of water. Then .01g of dried milk was added to the jar and it was gently mixed for 10 seconds. After this the top of the jar was removed and it was left out until the next lab session. All of this was carried out in accordance with the provided lab manual (Bentley, 2015).

Data/observations- The transect was located immediately in front of the main entrance to Hurst Hall on the Eric Friedheim Quadrangle. It was mostly cut lawn grass with a significant portion consisting of mulch and soil with planted bushes. Abiotic components included: the pillar of a monument on the quadrangle, he soil/mulch mixture of the bushes, soil underneath the grass. The biotic factors included: grass, a tall grass-like plant, flowering bushes, and a dense bush.

Conclusions- It was clear that the assigned transect was the "Manicured Grassland" transect. A better understanding of the transect was acquired and this may prove useful in future endeavors. The Hay Culture Infusion for next lab seemed to be properly mixed and will hopefully lead to promising results in a week. Hopefully these next lab's results increase the data derived from he transect and also contribute to the understanding of ecosystems on the whole.

References- Bentley, Meg. 2015. A Laboratory Manual to Accompany: General Biology II. American University: Washington, DC. Pg.16-17

TEST Nick Carey

Bold texttest AP