User:Nicole Bonan/Notebook/Biology 210 at AU

Lab 2: Identifying Algae and Protists

Nicole Bonan

TA: Alyssa Pedersen

Lab Section: D01

July 2, 2014

Introduction

The purpose of this experiment was to use a dichotomous key and a microscope in order to identify four organisms in the Hay infusion culture created in the previous lab. A serial dilution was then carried out in order to create samples of the culture that would be incubated in separate petri dishes of agar and tetracycline. It was hypothesized that if organisms existed near the top of the Hay infusion culture, then they would be able to photosynthesize, and that if organisms existed near the bottom of the culture, then they would be protists. In the following report, the methods used, results, data, and interpretation of the results of the experiment will be discussed.

Materials and Methods

First, a sample of the Hay infusion culture was taken from near the top of the culture using a disposable pipette. A wet mount was created using a drop of the culture sample, a drop of Protoslo, a cover slip, and a slide. The slide was placed under a microscope, and two organisms in the sample were observed and identified using a dichotomous key. The same procedure was then carried out using a drop of the Hay infusion culture taken from near the bottom of the culture.

Next, serial dilutions of the culture were made after swirling the Hay infusion culture to mix up all of the organisms in the culture. The first serial dilution was 10^(-2), which was created by adding 100µL of the Hay infusion culture to a test tube containing 100mL sterile broth. The next serial dilution was 10^(-4), which was created by pipetting 100µL of the 10^(-2) dilution into a separate test tube of 100mL of sterile broth. The third serial dilution was 10^(-6), which was created by pipetting 100µL of the 10^(-4) dilution to a separate test tube containing 100mL of sterile broth. The final dilution was created by pipetting 100µL of the 10^(-6) dilution into a separate test tube containing 100mL of sterile broth. A 100µL micropipette was used for all of the pipetting in the serial dilutions.

The serial dilutions were then plated onto agar plates. 100µL of each serial dilution were pipetted, using a 100µL micropipette, onto separate agar plates and spread across the agar using a sterile glass rod. Then, separate 100µL samples of each dilution were pipetted onto separate agar plates that contained tetracycline and were spread across the agar using a sterile glass rod. All of the plates were covered, labeled with the initials of the lab members, and set on a windowsill to incubate at room temperature until the next lab. The tetracycline plates were also labeled with a "T".

Results

After having incubated since the previous lab, the Hay infusion culture appeared to be about the same opaqueness as lemonade. There was sediment and plant matter at the bottom of the liquid, while the top of the liquid seemed relatively free of this type of matter. The liquid was a light brown color, and the matter at the bottom was very dark brown. The culture had an odor of algae and mildew.

Two organisms were identified from the top of the culture and from the bottom of the culture for a total of four identified organisms. The two organisms identified from the top of the culture were paramecium and amoeba. The paramecium

Tables and Graphs

The above table shows information about each of the four organisms that were identified in the Hay infusion culture using a dichotomous key. The four organisms identified were paramecium, amoeba, chlamydomonas, and colpidium.

Lab 1: Biological Life at AU

Nicole Bonan

TA: Alyssa Pedersen

Lab Section: D01

June 30, 2014

Introduction

Natural selection is a major factor that causes evolution. The evolution of a species can create biodiversity, as a species can evolve different characteristics, splitting one species into two. Eventually, as natural selection continues, an entire ecosystem can be formed. An ecosystem consists of all of the abiotic and biotic factors in a certain area. Each organism has a niche, or a certain set of environmental requirements, within the ecosystem. An ecosystem can be divided into transects, which are just smaller areas of a larger ecosystem.

The objective of this lab was to observe the characteristics of a niche in a transect of the American University ecosystem and to create a Hay infusion culture from the soil in the transect. In the following report, the methods, results, data, and interpretation of the results of the experiment will be discussed.

Materials and Methods

First, a transect of about 20m x 20m at American University was observed. The area was noted as "Transect 5". Pictures of the transect were taken and notes about the abiotic and biotic components of the transect were written. Next, a sample of the soil was taken in a conical tube. 10g of this soil sample were then added to 0.1g dried milk and 500mL Deer Park water in a plastic jar in order to make a Hay infusion culture. The jar was labeled as "Transect 5 TJ NB".

Results

The area that was observed, Transect 5, was a garden near the entrance to AU's campus. The transect was surrounded by paved sidewalks and was situated in a gully between two roads and a dorm building. The transect was hilly and had many biotic and abiotic components, most of which were landscaped and not naturally-occurring. Most of the biotic components were plants, and most of the abiotic components were stones.

Tables and Graphs

Table 1: Biotic and Abiotic Components of Transect 5

Biotic Components	Abiotic Components
Birds	Rocks and Stones
Gnats	Clay, mud, and mulch
Bees	Benches
Ferns	Stone pathway
Spots of Mosses	Drainage ditch
Liriope
Trees
Junipers
Ants
Clovers
Plants

The above table includes all of the biotic and abiotic components of Transect 5 that were recorded. The biotic factors are listed on the left and the abiotic factors are listed on the right.

Figure 1: Aerial View of Transect 5

The above figure shows an aerial view of Transect 5. Transect 5 is surrounded by sidewalks, which are colored in yellow. The bushes and trees appear as green circles, the stones appear as grey circles, and the benches appear as brown rectangles. The grey area surrounding the sidewalks are roadways, and the brown structure to the bottom left of the transect is a dorm building. Light green areas represent grass; light brown areas represent mulch and soil.

Figure 2: Transect 5, Image 1

The image above is of Transect 5. The image shows part of the drainage ditch, made of stones, and a mulched area to the right that includes different types of plants. A path with patches of moss winds through the center of the image, stopping at the stones.

Figure 3: Transect 5, Image 2

The image above is of Transect 5, and the image was taken to the left of Figure 2. The image above shows the continuation of the mulched area from Figure 2, which includes a tree surrounded by ferns and other plants. The image also shows a second drainage path for runoff. A paved sidewalk, shown in the back of the image, surrounds most of the transect.

Figure 4: Transect 5, Image 3

The image above is of Transect 5. This image was taken 180 degrees from Figure 3. It shows the path, continued from Figure 2, which dead-ends into the bench. A large bush is situated next to the bench, and behind the bench are grasses and a sign describing the garden. Behind the grasses is a mulched area with junipers, which eventually meets a sidewalk on the edge of the transect.

Figure 5: Transect 5, Image 4

The image above is of Transect 5. This image was taken to the left of Figure 2 and to the right of Figure 4. The image shows a second bench, which sits along the path that runs through the transect. Behind the bench are grasses and a tree, and behind those is the continuation of the mulched area from Figure 4, in which junipers are planted. The drainage ditch from Figure 2 is continued in this image; it consists of sones and runs through the lefthand side of the image.

Discussion

Summary of BG info.

The purpose of this experiment was to observe a transect (Transect 5) American University in order to learn about the types of biotic and abiotic factors in the transect, how they interact with each other, and how these interactions affect their niches. The result of this experiment was that many different abiotic and biotic components were observed in Transect 5 at American University. Most of the biotic components were plants, while most of the abiotic components were stones. The transect was landscaped and not naturally-occurring.

Sources of error

There were many implications of the data that was observed in Transect 5. One implication was that humans had shaped the land in order to suit their needs, and from there, an ecosystem was developed. For example, the drainage ditch that ran through the transect existed because humans needed a drainage system to conduct water away from roads during storms. The area around that drainage system was then landscaped in order to look appealing to humans. The landscaping included plants and trees, which helped to create an ecosystem for birds and insects in the area. Another implication of the data was that Transect 5 had very nutrient-rich soil in the areas where plants and trees were growing. These species were leafy and healthy, which indicated that they were getting the nutrients and water needed to sustain themselves. A final observation of this experiment was that the transect was very clean and organized, in that plants were planted in specific areas and there were few weeds that seemed to be growing randomly throughout the transect. The implication of this observation was that the niches of many species within the ecosystem was controlled by humans; humans decided where plants would be planted, and they worked to get rid of unwanted weeds.

The results of this experiment could be used by others to observe the difference between natural and artificially-created ecosystems.

This experiment applies to real world issues