IB Lab #1: Isopod Activity

1. Aim: The aim of this experiment is to see if Pill bugs prefer salt, sugar, or tap water in a specific amount of potting soil.

2. Safety Information: Cation must be used when handling the scissors needed to do this experiment because they have a sharp point that could potential hurt someone. To avoid getting hurt by the scissors, never run with them and always carry them with the point pointing towards the ground. Also make sure that there are no fingers or hands in front of the scissors while they are being used.  

3. Introduction/ Background: Do Pill bugs prefer saltwater, tap water, or sugar water saturated potting soil? Well, Pill bugs are invertebrates that can be found in a myriad of places throughout the world. They like to live in damp habitats (i.e under rocks, dead leaves, and logs). They survive on decaying vegetation. They are born from eggs, and sheds their outer shell, or exoskeleton, four to five times throughout their lives. Pill bugs have gills so their breathing can be affected by the level of moisture in different types of environments. They are also most active at night and prefer higher levels of soil, so the amount of soil they are living in could affect their activity. I collected my bugs from my family’s garden in my backyard and from potting soil that I found around San Bruno park. I created the habitat I would keep them by, first, putting a moist paper two at the bottom of a plastic container. Then I put soil and a little bit of vegetation on top of that, and finally, I put the Pill bugs in their new habitat. Every day, after class, I would make sure to wet the dirt with a little tap water.

  • Hypothesis Statement: I believe that the Pill bugs will prefer the potting soil that’s saturated with tap water more than the soil that’s saturated with salt or sugar water. This is because they are used to living in soil that’s naturally unsaturated. Pill bugs, being crustaceans, have gills and need water to breathe. All living things desire to be in a area where they can live comfortably and thrive; thus, if the water the Pill bugs are ingesting is not what they are accustom to and/ or if they find breathing too difficult, they will want to move to a more habitable area. Since their normal habitat consists of naturally saturated soil, they will most likely stay in the area that is most like naturally saturated soil-- the potting soil saturated with tap water.
Join now!

4. Methods/ Experimental Design:

- Independent Variable: the type of the water (sugar, salt, or tap)

- Dependent Variable: Pill bugs water preference (how many Pill bugs are in each type of saturated dirt)

- “0” Control: potting soil that’s saturated with tap water only

  • Control of outside variables: the amount of water, sugar, and salt in the potting soil, the type of potting soil

  • Materials:

- 6 small petri-dishes

- 2 large petri-dishes

- 8 Pill bugs

- 3 graduated cylinders

- 3 graduated droppers

- 62 mL of tap water

- 5 mL of ...

This is a preview of the whole essay