Paleozoic Era, geology homework help

1. Describe the major paleogeographic trends of the Cambrian period and how they affected patterns of sedimentation.

2. Describe the mass extinctions at the end of the Permian period. What are some probable causes?

3.Discuss the Paleozoic evolutionary history of two of the following:

a) fish

b) amphibians

c) reptiles

d) vascular plants

4.a) How do scientists distinguish between reptiles and mammals?

b) How did the marine invertebrates of the late Paleozoic differ from those of the early Paleozoic?

These are the questions. No need to write too much. 3-5 sentences for each question will be enough.