User:Emily R. Lafferman/Notebook/Biology 210 at AU

1/21/15 I love protists!

1/22/15 Identifying Algae & Protists The purpose of this lab was to become familiar with the use of a dichotomous key to identify organisms and in doing so, examine the different characteristics displayed by various algae and protists from Transect 1.

Methods The first procedure focused on learning how to accurately use the dichotomous key to identify known organisms on a wet mount under the microscope. Once comfortable with this skill, the dichotomous key was used to identify unknown organisms under the 4X and 10X objectives. The second procedure involved making wet mounts of samples from the hay infusion culture obtained the week previous. After noting all observations of these samples, the dichotomous key was again used to identify as many present organisms as possible. The third procedure required prepping and plating serial dilutions of samples from the hay infusion culture, once it had been swirled (allowing the settled niches of the organisms to blend). 100 mL tubes of sterile broth were labeled and 100 microliters of the hay infusion culture was micropippeted into the first tube and shaken. 100 microliters was transferred from tube 1 to tube 2 in similar fashion until all four tubes are ready (see diagram below for reference).

Agar plates were subsequently labeled and 100 microliters from each tube was transferred to each plate - this process was repeated for the plates containing antibiotic tetracycline. All samples were spread evenly across the plates in a sterile manner to avoid contamination and error. The plates were then set aside to incubate and room temperature for lab 3.

Data, Observations, & Findings Procedure I -unknown organism found under microscope was approximately 20 micrometers in length -colorless, swimming quickly with cilia, maintained an ovular body shape -> narrowed down to be colpidium sp

Procedure II: Hay Infusion Culture of Transect 1 sample presented a sour, foul odor, with a green, cloudy marsh-like appearance that had a thin solidified layer on top. After investigating more closely the nature of these organisms, Didinium for example, it can be observed that this life fulfills all necessary criteria for being alive: -It is made of cells, it has different levels of organization within it (note image drawn below) -It uses energy (in this case, likely the milk powder provided previously) -It responds to things in its environment (became slowed when in coming into contact with the paralytic agent) -It reproduces (which is apparent due to the vast number of individuals found within this sample - likely more to be found next lab) -It adapts to its environment (although this cannot be observed directly, this organism is displaying all signs of life even after being removed from its original environment of the transect to this culture sample) If this culture continues to flourish for another couple months, each population of organisms will likely compete with one another for space. The carrying capacity of this small jar is limited, so the fungi, bacteria, and protists present will both continue to coexist but not all individuals will survive due to the conditional limitations of this environment.

Conclusions Two organisms found in the sample are a part of the Volvocine Line, as the chlamydomonas and volvox identified can be found in environments with characteristics similar to those of Transect 1.

-ERL

1/26/15 Lab 1: Biological Life at AU

The purpose of this lab was to understand the role of natural selection in evolution by observing the traits of organisms that are members of the Volvocine Line under the microscope, as well as observe and record observations of a niche.

Methods In the first half of the experiment living slides of Chlamydomonas, Gonium, and Volvox were examined and observations were recorded in the table below. The mechanisms for motility, ways of reproduction, and colony size were all noted. The second part of the experiment consisted of visiting the assigned Transect on campus to develop our observational skills. A sample was collected in a 50 mL conical tube for a hay infusion culture to be made subsequently, and everything that went into this sample was recorded for later use. Once back to the lab, the culture was made by placing 10 grams of the sample into a large plastic jar along with 500 mLs of deerpark water. 1 gram of dried milk was added to provide food to any living organisms in the sample that may need it. The culture was gently mixed and the jar was left open in the lab for a week, after being labeled “Transect 1”.

Data, Observations & Conclusions All Data collected for the first half of the lab has been recorded in the table below:

Transect 1 considered to be the “Marsh” was full of life, even during the cold season. It is located close to Massachusetts Avenue, containing a drain, where any run-off can go. The ground was relatively soft and wet, due to recent snow-fall, but not yet fully frozen. Both biotic and abiotic components found within the transect were recorded in the table below. A photo of transect 1 has also been provided below. It is likely that once the culture incubates for a week, there will be a wide range of organisms to be found from Transect 1.

ERL