Four u tubes each have distilled water in the right arm, a solution in the left arm, and a semipermeable membrane between arms.

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.

What are the three stages of volcanic activity? a. active, magma, lava c. extinct, eruption, explosive b. eruption, quiet, explosive d. active, dormant, extinct