Describe some of the changes in the land and in life-forms that occurred at the end of the paleozoic era.

Continent regrouping in the Pangea and mass extinction of living organisms

Explanation:

At the Paleozoic era the continents started to regroup in in what has been called the supercontinent Pangea. The collisions caused by the formation of this super continent did form big mountain chains.  

At the end of the  Paleozoic era there were many complex animals as consequence of evolution, however, a massive extinction wiped out nearly all living organisms on the planet and only a few species survived