User:Madison Prieto/Notebook/Biology 210 at AU

February 5, 2016 Exercise 4: Plantae and Fungi

Materials and Methods Procedure one was to collect plant samples from our transect. We had to collect at least 500 grams of leaf litter.

M.P.

January 29, 2016 Exercise 3: Microbiology and Identifying Bacteria

Purpose The purpose of this lab is to examine the diversity of bacteria in our Hay Infusion. We will observe the diversity of the morphological characteristics of bacteria. By using Tetracycline, we will test for antibiotic resistance in bacteria. We will also use gram stains to identify different types of bacteria. Finally, we will use PCR and DNA sequencing to verify our identification of the bacterial species in our transect.

Materials and Methods

Procedure one was to observe the bacterial growth on the agar plates and count the colonies. Procedure two involved observing bacteria and cell morphology with prepared slides. We then prepared wet mounts and gram stains with the bacteria from our agar plates. To make a wet mount, sterilize a loop over a flame and scrape up a small amount of growth from the surface of the agar plate. Mix it into a drop of water on a slide and put a cover slip on the drop. Observe using 10x and 40x. To make a gram stain, sterilize a loop over a flame and scrape up a small amount of growth from the agar plate. Mix into a drop of water on a slide. Circle the area underneath the sample with a red wax pencil. Label the slides. Heat fix the air-dried slide by passing it through a flame three times with the bacteria smear side up. Rinse the stain off. Cover the bacterial smear with Gram's iodine mordant for one minute. Rinse the stain off. De-colorize by flooding the bacterial smear with 95% alcohol for 10-20 seconds. Rinse gently. Cover the smear with safranin stain for 20-30 seconds. Rinse stain. Blot excess water carefully with a kimwipe from the side of the slide and let air dry. Do not place a coverslip on. Focus with low magnifications. Procedure three involved setting up PCR. Label two PCR tubes with transect number, colony identifier, and group number. Add 20 microliters of primer/water mixture to a labeled PCR tube. Mix to dissolve the PCR bead. Using a sterile toothpick, pick up a small amount of a bacterial colony. Submerge the toothpick in the primer/water mix and twist for 5 seconds. Discard toothpick. Cap the tube and place in PCR machine.

Data and Observations Serial Dilutions Results Table:

Bacteria Characterization Table:

Colony Morphology:

Gram Stain Tetracycline 10^-3:

Gram Stain 10^-5:

Conclusion

M.P.

January 22, 2016 Exercise 2: Identifying Algae and Protists

Purpose The purpose of this lab is to use a Dichotomous Key to identify protists from our Hay Infusions and to learn the defining characteristics of protists. We will also identify and characterize the protists in our transect. We then did serial dilutions to plate the bacteria and characterize the bacterial diversity.

Materials and Methods Procedure one involved making a wet mount from the Hay Infusion to observe with the microscope at 4x and 10x. Focus on an organism, describe it, and record its size. Use the Dichotomous Key to identify organisms. Procedure two involved prepare for next week’s microbiology lab by preparing agar plates. We obtained four nutrient agar and four nutrient agar plus tetracycline plates. We performed serial dilutions for the bacteria to grow on each plate. We added bacteria to each plate and let the plates sit at room temperature for a week.

Data and Observations

Our Hay Infusion was filled halfway with brown dirty water. There was some dead plant life sitting at the bottom on top of sand or dirt that had collected at the bottom of the jar. All of the plant life looked destroyed. There was a sort of film over the surface of the water. We took samples from the top, middle and bottom of the Hay Infusion and viewed the samples under a microscope.

We used the Dichotomous Key to determine what protists were living in our Hay Infusion.

Description of cell from bottom of hay infusion: -Cell is colorless -Cell is stagnant -Cell is not spherical -Shape of cell remains constant -Seems as if cell has very thick cell walls -Parts of cell would range from 2-30 ocular spaces at 100x -This protist sample is a type of algae known as Pandorina.

Description of cell from middle layer of hay infusion: -4 ocular spaces (at 10x objective) -small body -oval shaped -fast swimmer -Colpidium

Description of cell from top layer of Hay Infusion: -random, quick movements, -cell compresses as it is moving -10 ocular spaces -Stentor

Another cell from top layer of Hay Infusion: -5 ocular spaces -colonies -Gloeocapsa

Another cell from top layer of Hay Infusion: -150 ocular spaces -resembles a large blob -Hydrodictyon

Pictures of Protists:

Conclusion In this lab, we identified that the samples from our Hay Infusion were full of life. In our samples, we saw both algae and protists, supporting our hypothesis that there would be many biotic factors in our hay infusion. We also used a Dichotomous Key to characterize and learn about the protists and algae in our Hay Infusions. Next week's lab will reveal even further analysis on the biodiversity of our transect through examining the bacterial diversity from the samples.

M.P.

January 15, 2016 Exercise 1: Examining Biological Life at AU

Purpose The purpose of this week's lab experiment was to examine and compare different members of the Volvocine Line and to examine the biodiversity on the campus of American University. At the end of the lab, we set up a Hay Infusion with abiotic and biotic compontnets found in our transect.

Materials and Methods Procedure one involved examining members of the Volvocine Line: Chlamydomonas, Gonium, and Volvox. We recorded the colony size, number of cells, specialization of these cells, and whether the cell was isogamous or oogamous under the microscope. Procedure two involved going to our transect and recording everything we observed. We also took samples of our transect and brought the samples back to the laboratory. Procedure three involved making a Hay Infusion. To do this, we placed 10-12 grams of our sample into a jar with 500 mLs of deerpark water, added 0.1 gram of dried milk, and mixed the jar for 10 seconds.

Data and Observations Transect Four included many different biotic and abiotic factors. The abiotic factors included rocks, water, soil and benches. The biotic factors included trees, bushes, flowers, fishes, and many organisms. This transect was interesting to survey and collect from. There is so much plant life and animal life, although we were only able to view the organisms under the microscope. A majority of the plant life was wilted and brown due to the cold weather.

Sketch of Transect Four:

Images of Transect Four:

Conclusion Transect four had many abiotic and biotic components to it. These abiotic and biotic components will help us examine the biodiversity at AU. Further experiments will show the different types of organisms that live in transect four at American University.

M.P.