Tetrahymena Lab Report

4. EVALUATION AND CONCLUSION CONCLUSION The data did support my hypothesis as stating that the larger a cell is, the harder it is for diffusion to take place as the surface area to volume ratio decreases throughout evidence supported. There is a pattern in table 5 shows that, the surface area to volume ratio decreases when the agar jelly increases in size from 1cm to 3cm cube by a ratio of 6 to a ratio of 2, showing that average rate of diffusion which decreases as the size of the agar increases has a linkage to cells as cells increase in sizes.

Cytoplasmic streaming was measured 4 times after flushing the cells with pond water, at 5 minute intervals

Tetrahymena in the 5% ink showed a higher stained vacuole count that those in 1% ink. This supported our hypothesis that the Tetahymena in a higher concentration of ink would show more staining, because there is more ink around for them to consume. Differing results were found in a similar experiment by Bazzone (2000), as cells in a higher ink concentration showed fewer vacuoles than those at a lower ink concentration. This experiment followed the same procedure, but expanded the ink concentrations to include 10% ink and examined cells at the timepoints 2, 10, 20, and 30 minutes (Bazzone, 2000). This study did not find an explanation for why these results occurred (Bazzone, 2000). Since our numbers of vacuoles of 1% and 5% ink were nearly identical for each time period, it is possible that if we repeated the experiment and counted more

In this assignment I will be describing the microstructure of a typical animal cell and the functions of the main cell components. Describing and explaining the factors the ways in which materials move in and out of cells. I will also be analysing the role of the phospholipid bilayer in terms of movement of materials in and out of cells.

The experiment was divided over the span of six days. For this procedure, Cav1.2 will be mainly referred to. On a Thursday, start with clean test tubes, the Luria broth, and either the Cav1.2, Connexin 43, or N-Cadherin (if a

Purpose: The purpose of this experiment is to gain knowledge of the functions and operations of the compound light microscope and an immersion oil lens by observing prepared slides of various bacteria and blood slides. We are also learning to indentify and observe the various shapes and characteristics of bacteria, as well as, yogurt cultures (fresh and prepared) and blood samples under a microscopic view. We will also be able to distinguish between blood cultures and bacteria specimens.

First, 10 mL of bromothymol blue solution and 150 mL of aquarium water were poured in the 600 mL flask. Then carbon dioxide was exhaled through the straw in the flask until the mixture in the flask turned into a greenish/yellowish color. Next four test tubes were filled with the newly created mixture, filling it to within 3 cm from the top of the test tube. An Elodea sprig was inserted into two of the four test tube then parafilm was fastened to the top of all four of the test tubes. Then aluminum foil was used to completely cover one test tube containing Elodea and one without Elodea.

Observation of phenotypic appearance was taken using a dissecting microscope at 50x magnification and a

Bacteria that can tolerate the high concentration of salt in the media are from the Staphylococcus genus. A sample of unknown A was also used to stab a gelatin test tube, which contains the gelatinase enzyme that breaks down the gelatin and changes the media from solid to liquid. A sample of the same unknown along with a sample of unknown B was then used to stab a citrate test tube each. The citrate test is used to determine whether the bacteria utilizes citrate as a carbon source. If the bacteria used the citrate, the color of the media turns green, but if the citrate was not used, the media remains blue. The color change in the media is due to the presence of the pH indicator bromothymol blue. Afterwards, a sample of both unknown B and unknown C were used to make single line inoculations on both an Eosin Methylene Blue (EMB) and a Salmonella Shigella (SS) plate. Each plate was divided by a a line in half so that unknown B was inoculated on one side and unknown C was inoculated on the opposite side. The EMB plate contains lactose and dyes eosin and methylene blue. The media is used to differentiate between lactose and non-lactose fermenters. The SS plate also contains lactose in addition to bile salts and brilliant green (dye) to select for species of Salmonella & Shigella. The media also contains some

Triton is the largest satellite that orbits the planet Neptune. The surface of Triton is riddled with cryovolcanoes that emit volatiles such as water, ammonia, or methane, instead of the molten rock that volcanoes on Earth emit. It has an atmospheric pressure of 14 μbar (1/70,000th of Earth’s surface pressure) and a gravitational constant of -0.779 m/s2. The average surface wind speeds are 5-15m/s, and the average temperature is 35 K.

The observation under the microscope of a cell of an onion skin soaked for 15 minutes in a 0.5 molar sucrose solution showed a cell membrane just beneath the cell wall. The cell wall had a rectangular shape. See diagram 3 for sketch. The cell and its surrounding were in an isotonic solution. The two solutions in the cell and out (0.5 molar sucrose solution) of the cell were homogenous. No net movement of water and change in the cell structure was observed. The components of the solute and solvent were evenly intermixed. The concentration of solute and solvent on either side of the cell membrane was equalized. Because the onion tissue didn’t get any water the cell was flaccid and nonturgid.

2. Take the cultures into a dark room at the same times each day. You can use a dim source of light to help you while you work. Make sure you keep the light as far away from the cultures as possible. To stimulate bioluminescence, completely close the caps of each tube and flip upside down. You should see a clear blue light near the bubble moving through the tube. Record your observations and brightness ranking in your lab notebook.

In the 10-3 pasteurized sample, the plate exhibited 71,000 cells/mL. The results of the additional dilution samples contained too few colony forming units to count. However, in the 10-7 dilution, although the plate demonstrated 12 colonies, there should have been no colony forming units on this plate. The reasons for this could have been that this sample was contaminated from “double-dipping” the sample before dispensing it onto the plate or when using the pipette, it mistakenly was inserted in a higher concentration sample and then immediately to a lower concentration sample before it was dispensed onto the plate.

The second part of the experiment was to observe a human cheek cell. It looked similar to the size and shape of the onion cell. In the cheek cell there were nine visible parts: the ribosomes, the Golgi apparatus, the cytoplasm, the vacuoles, the endoplasmic reticulum, the lysosomes, the mitochondria, the cell membrane and the nucleus. The human cheek cell also did not contain chloroplasts because it is an animal cell. An animal cell does not require chloroplasts because it never goes through the process of photosynthesis. The cheek cell also did not have a cell wall surrounding it, this is the case because animal cells do not have a cell wall they only have the cell membrane. In conclusion there were some major differences between the onion cell and the cheek cell such as appearance and organelle

To investigate the rate at which Tetrahymena consume “food” we preformed two labs. In the first lab, we had Tetrahymena consume India ink and then measured the number of food vacuoles over various time periods. Our hypothesis was that there would be more vacuoles visible over a longer length of time in the Cytochalasin and Colchicine than in the vehicle (70% ethanol) because the ethanol does not affect actin filaments or microtubules, whereas the other two do. In our Lab #4 experiment we observed the time it took for the vacuoles to consumes just the India Ink and in the Lab #5 experiment we added drugs to see how it would affect the rate at which the Tetrahymena consumed the India ink.