Isopod Experiment Lab Report

The lab handout provided by the instructor was used as a guideline to conduct this experiment. The only difference was the organism used and data collection period. For this experiment, pill bugs and crickets were utilized. Also, data was collected for a period of 12 minutes.

The dependent variable is pulsation rates of L. variegatus before and after they were in the treatments. The standardized variable of this experiment would be the temperature of the surroundings of the L. variegatus, the three pulsation rates taken for each worm before and after the treatments, and also the amount of time each worm was kept in their respective treatments. The level of treatment for this experiment would be ten because of the six different concentration treatments of caffeine and nicotine along with the four household drugs. The sample size of the experiment differed from some treatments to other. For the three different concentrations of caffeine and nicotine, the sample size was 18 black worms each. The sample size of the control treatment of week 1 was 6 black worms. 12 black worms were used for the control of week 2, decaffeinated coffee and instant coffee. 11 black worms were used for the tea treatment and 15 were used for the tobacco treatment. There were three replications of the pulsation rate readings per worm before and after the treatment. With all this information we were able to get the results we got.

The first variable tested was phototaxis, the movement toward or away from light. To do this, we used an empty petri dish and filled the bottom of it with filter paper. We then added five sowbugs to the petri dish and placed a lid on top. After leaving the sowbugs alone for three minutes to get acclimated to their new environment, we placed a lamp directly over the petri dish. Then we laid a piece of cardboard over the petri dish to cover exactly half of it, leaving the other half exposed to the lamp. We want the cardboard to cover close to half of it as possible to make the data as accurate as possible. The lamp was then turned on and the number of sowbugs in the light and dark locations were recorded every minute for the next twelve minutes. As shown in Table 1, we determined that sowbugs are effected negatively by phototaxis.

Pill bugs live in an outside environment where they are able to get the necessary amount of energy from organic matter. This environment is where water and organic matter is plentiful. In there natural habitat, pill bugs are found in dark, damp places. Living in moist places is important for pill bugs so they can take in enough water, and if water is not available, they group together to prevent water loss. Pill bugs most often live in dark places because they have a negative photo taxis. Darker places also tend to be cooler and damper. Each experiment connected to how the pill bugs would behave in a certain environment. We were able to test these experiments in a laboratory way to see if the natural environments were also true.

1The isopods will gather in the wetter environment instead of the dry environment. 2The isopods will have an affinity to a more basic region than an acidic region. 3The isopods will tend to gather in the environment with a greater amount of light, than an environment with no light. 4The isopods will take a liking to a warmer temperature environment than a cooler temperature environment.By looking at the data you can see that there is a preference among isopods to favor an environment that is cold, wet, basic, and dark. We included the observed data as well as the expected data. Our expected data show what the information would look like if it came from a null universe. To come from a null universe means that the data will have no difference,

Wet and Dry Environments To find whether Pill bugs gravitate toward a wet or a dry experiment, two coffee filters were cut to the size of the petri dish and placed inside, however one was dampened before being placed on the bottom. Dirt was then added on top to promote a more realistic environment and five Pill bugs were placed in each side before starting to prevent bias on an environment. A log was taken every thirty (30) seconds for ten (10) minutes on how many bugs were in each chamber and a graph was then made to show the changes of the bugs' positions over time. Again, if a Pill bug was in the transgression tunnel he was determined to be in a dish by the direction he was moving or the way it's head was facing.

Two circles were drawn directly across from each other on plain white paper. One was drawn with a black Sharpie marker, and the other was drawn with a black ballpoint pen. Three separate termites were dropped directly in the middle of the two circles, and their reactions were recorded for sixty seconds. This was repeated once for each termite.

Do you observe a selective advantage or disadvantage for the red or blue beads on the blue habitat? Why?

The ocean floor is a very dark and is filled with algae however, crabs that live here can still easily catch and eat plankton. Scientists are wondering, is it the crab’s other senses doing the job or is it just there sight? On the ocean floor not much light gets in which leads everyone to think that the crabs can't see however, some light does reach the crabs and the plankton the crabs eat. Most visible light does not reach the ocean floor in normal conditions except yellow light and green light. Since the plankton reflects all visible light the plankton would appear yellowish green to the crab’s eyes. Even though the green and yellow light reaches the floor in normal conditions the area where the crabs live is packed with algae. According to evidence cards F and G algae reflects green light but all the other colors of visible light are absorbed with algae. This states that only green light has a large chance of making it to the bottom so the crabs can see the plankton.

The mealworms showed kinesis behavior because they did not all go away from either the fish food or the potato, they kept crawling through both of those chambers. If they were to show taxis behavior then the mealworms would find their way into the chamber they liked the best because taxis behavior is deliberate. The data shows that at 30 seconds the mealworms liked the fish food more than the potato because there were 8 mealworms in the chamber with the fish food and 0 with the potato. However as time went on the mealworms leveled out because at 10 minutes there was 6 in fish food, 5 in potato, and 4 in the control group. The data really doesn’t show if the mealworms liked one food choice over another, but the mealworms did tend to chose the fish food over the potatoes a little more. Overall, there wasn’t really any sources of error doing this, but if I were to do this again I wouldn’t chose to do potato and fish food again. The reason for this is because the mealworms didn’t react to those 2 options very well. I would prefer to do light vs. dark because I think that would actually affect the mealworms more. To improve this experiment I would have 30 mealworms instead of just 15 and I would increase the time we observe them to maybe get a better outcome in the

After the experiment had been conducted, the investigator concluded that the original hypothesis did not fit the outcome of the testing of the Beetle Robot. While it was hypothesized that the device would move and react in the same

2. Place 10 randomly selected sowbugs in each of the 3 empty tin bowls for 3 minutes to allow them to acclimate to the environment.

1. Observing the pillbug: examine the pillbug’s shell and body, shell shape, color, texture, number of

The barnacles were tested using a small cup filled with water which has a small rock with barnacles on it. Before the experiment was conducted, the barnacles were fed food. The change in cirri beats over one minute was determined. The average decrease of cirri beats per minute was 12.6. Although the manipulated trial was inconsistent, it is still logical to conclude that the

The containers were plastic and 18 by 15 by 6 centimeters long. Prior to the experiment being performed, the crickets had spent a week in these residencies. Along with the crickets in the plastic containers, there was wet pieces of paper towel and a slice of carrot.