BACKGROUND:

There are many organisms that live on Earth. Some have feet, some swim, and some fly. They come in all shapes and sizes. They all have two things in common: (1) they have to reproduce and (2) they have to eat. In order for humans to determine how many organisms there are, scientists developed a way to name and group them. The more we learn about organisms the more we refine our groups. In ancient Greek times, Aristotle grouped things into Animal and Plant. Now we group them into 6 kingdoms including: Animals, Plants, Fungi, Protist, Eubacteria (true bacteria), and Archaeobacteria (primitive type of primitive bacteria.)

Students have previously learned about large animals, and now we turn their attention to the smaller animals, or those called invertebrates. The animal kingdom is divided into two major groups according to the presence or absence of a spinal column (backbone). Animals with a backbone are called vertebrates and those without are called invertebrates. The development of the backbone was a major step in large animal evolution because it allowed these organisms to develop a successful life on land.

PROCEDURE:

1. Ask students which animals they think belong to either vertebrates or invertebrates. If they say "insects" or "crabs," put them under "invertebrates." As they give you examples, group them into the two groups on the board. Get the students to see that vertebrates tend to be larger organisms. Show students examples from the Display Kit of Invertebrates.

2. Use the following diagram to illustrate students that invertebrates are a diverse group. They account for most of the biomass on Earth. Go over the key characteristics of each group. Students will be looking at the invertebrates in lab by observing with their eyes and the microscope. However, they need to develop a way to describe these organisms.

3. Have students take notes. If you have internet access you may want students to start to find more information that will help them describe the different samples they will see in lab. Use some of the children’s search engines.