Earthworm Lab
1. Background
The earthworm (may it rest in peace / pieces) that our group recieved was largely moving at its anterior end. It had orange and red and orange blotches and was lighter on its underbelly. It was semi-transparent and had darker segment divisions. At first, it was moving around in the dish, but after Jeremy rubbed it in his hands, it began to move more because it was warmer. We continually tried to flip it over to the dorsal side, but it was a fighter and kept rolling over. Our worm displayed both kinesis and taxis. It moved away from our touch (taxis) but also towards the wet paper towel (kinesis). We can deduce, therefore, that the worm prefered a wetter environment. Our worm belonged to the phylum Annelida, which contains invertebrate, protostome coelomates with bilateral symmetry, nephridia for excretion, blood that contains hemoglobin, and a closed circulatory system. Finally, our worm was a hermaphrodite. Unfortunately, it suffered an untimely demise...
2. Question
What concentration of water will the worm prefer?
Hypothesis: The environment with the greatest concentration of water will cause the greatest increase in the earthworm's weight because water will diffuse into the worm.
Hypothesis: The environment with the greatest concentration of water will cause the greatest increase in the earthworm's weight because water will diffuse into the worm.
3. Procedure
1.) Fill the control container (the middle container) with 60 mL of soil.
2.) Fill the outer four containers with 100mL of soil.
3.) Add 50mL of water to the container 1, 25mL of water to the container 2, 10mL of water to the container 3, and 5mL of water to the container 4.
4.) Place the earthworm in the center container.
5.) Observe the earthworm's response to its environment.
2.) Fill the outer four containers with 100mL of soil.
3.) Add 50mL of water to the container 1, 25mL of water to the container 2, 10mL of water to the container 3, and 5mL of water to the container 4.
4.) Place the earthworm in the center container.
5.) Observe the earthworm's response to its environment.
4. Data
5. Summary and Analysis
Dependent Variable: container that the worm was attracted to
Independent Variable: varying amounts of water (mL) in each container
What does your data mean? If the worm is attracted to a certain container, than the container likely provides the optimal environment, in terms of water concentration, for the worm.
How does your earthworm's reaction and behavior relate to survival? If the worm is attracted to a certain container, then that container is likely representative of the best environment for the worm. Therefore, this is the environment that will increase the survival rate of the worm by providing the optimal water level. The earthworm spent a few seconds in the 5mL container before going back to the 0mL container. Perhaps the water concentration was too great, and so the worm went back to a less concentrated container.
Sources or error / Items to Correct in Repeating: The worm spent a few brief seconds in the 5mL container before going back to the original container. Therefore, this data was largely inconclusive because the worm was not exposed to all environments. Therefore, the effect of each environment upon the worm could not be measured. To improve the lab, the mass of the worm could be measured before and after being placed in certain environments to measure the effect of each environment (diffusion!) on the worm. If the same experiment needed to be repeated, I would place the worm in each environment and measure how long the worm spent in the environment before moving back to the control (0 mL) container.
Independent Variable: varying amounts of water (mL) in each container
What does your data mean? If the worm is attracted to a certain container, than the container likely provides the optimal environment, in terms of water concentration, for the worm.
How does your earthworm's reaction and behavior relate to survival? If the worm is attracted to a certain container, then that container is likely representative of the best environment for the worm. Therefore, this is the environment that will increase the survival rate of the worm by providing the optimal water level. The earthworm spent a few seconds in the 5mL container before going back to the 0mL container. Perhaps the water concentration was too great, and so the worm went back to a less concentrated container.
Sources or error / Items to Correct in Repeating: The worm spent a few brief seconds in the 5mL container before going back to the original container. Therefore, this data was largely inconclusive because the worm was not exposed to all environments. Therefore, the effect of each environment upon the worm could not be measured. To improve the lab, the mass of the worm could be measured before and after being placed in certain environments to measure the effect of each environment (diffusion!) on the worm. If the same experiment needed to be repeated, I would place the worm in each environment and measure how long the worm spent in the environment before moving back to the control (0 mL) container.