The following is a necessary tool when working on a computer:.

Explain how earth is like a giant bar magnet. how is our magnetic field made?

The different forms of a gene for a given trait are called .

Which statements about the two fossil images are correct? 1. cave bears are ancestors of plateosaurus. 2. plateosaurus were present on earth before ostracoderms. 3. ostracoderms were the first to die. 4. plateosaurus died after the ostracoderms. 5. cave bears are the oldest fossils.