It is called the parent material because it is the beginning of the other layers. Since a lot of parent material is rocky it is sometimes called bedrock. The next layer has lots of soil and rocks, it is called the subsoil. The top layer is full of soil and organic material like plants and leaves. This organic material gives the soil a darker color.
Worms Add a small layer of chocolate chips to the bottom of the cup for bedrock.
Add a layer of crushed Oreo cookies for you topsoil. For fun, stick a gummy worm in the topsoil. Why not make a soil profile breakfast. Stack different layers of your favorite cereals to make a soil profile. You can even use Fruity Peebles or Trix to look like the grass and flowers on top.