User:Student 65/Notebook/Biology 210 at AU

January 21, 2016 - Exercise II: Identifying Algae and Protists

Purpose:

The purpose of this experiment was to observe unicellular eukaryotic organisms in order to further our understanding of them. We will practice important techniques used to identify protists and algae. Specifically, a dichotomous key will be used to characterize and identify the unknown organisms from our Hay Infusion. Preparation for the next lab

Materials and Methods:

Hay Infusion Culture Observations - Observe the culture created last class and record all observations (i.e. smell, appearance). Make two wet mounts from the culture and observe under the microscope and determine which protists and/or algae are present using the dichotomous key. Record all observations, including size, motility, are they photosynthesizing, etc.

Serial Dilution Preparations - Mix Hay Infusion Culture with swirling technique. Combine 100μL of the culture with 10mLs of broth in a tube labeled 10-2. Combine 100μL of the 10-2 dilution with 10mLs broth in a tube labeled 10-4. Combine 100μL of the 10-4 dilution with 10mLs broth in a tube labeled 10-6. Combine 100μL of the 10-6 dilution with 10mLs broth in a tube labeled 10-8. Plate 100μL of each serial dilution on properly labeled nutrient agar plates. Plate 100μL of each serial dilution on properly labeled nutrient agar plates plus tetracycline.

Figure 1: Diagram of serial dilution procedure

Data and Observations:

Figure 2:

Figure 3:

Conclusions and Future Directions:

January 14, 2016 - Exercise I: Examining Biological Life at AU

Purpose:

The purpose of this experiment was to observe a specific 20 by 20 meter transect of land here at American University with which we will later characterize the different forms of life inhabiting that specific transect (the protists, bacteria, plants, invertebrates and animals). A hay infusion culture was made using a sample of the soil from the transect and will be used to analyze the protists and invertebrates from the specific niche. Our group hypothesized that our hay infusion culture will yield a variety of different organism, specifically protists and algae.

Materials and Methods:

For transect - Identify the transect (marked by four popsicle sticks with the number 1 on them). Record all observations of the transect, including its topography and location. Take a photo of the transect and draw an ariel-view diagram of the transect, making sure to note both abiotic and biotic features. Collect a sample from the transect to be used in the hay infusion.

For Hay Infusion - Mix 10-12 grams of collected sample, 500 mLs deerpark watered 0.1 gram dried milk in a closed, labeled jar for 10 seconds. Remove lid to jar and let sample sit in safe place in lab until next lab period.

Data and Observations:

The transect was located to the North East of Hurst Hall on the other side of the cross walk. It is a flat section of land with a sidewalk on one side and a cement fence on the other. The transect contains a variety of different biotic and abiotic components and some manmade components (light posts, sprinklers, etc.). Some of the biotic components observed include: a large tree, smaller trees and bushes, grass, organisms living in the soil, and potential animals living in the environment. The abiotic components of the transect included: soil, the sprinklers (a source of water), light (from the light post), and litter (a straw and cigarette).

Figure 1: Photograph of the transect from the North East side (facing South West)

Figure 2: An ariel diagram of the transect with abiotic and biotic factors labeled

Conclusions and Future Directions:

After observing the transect, it can be concluded that there is a variety of different abiotic and biotic components to our transect. The next step is to analyze what niches are present in our ecosystem. The hay infusion will be observed in the next class, with which we hope to gain a better understanding of our transect.

--Emily J. Kinneston 17:28, 2 February 2016 (EST)