WS 7.7ab

Unit 7
Big idea 7, concepts a and b:
Identify major developments that occurred during Precambrian time and the Paleozoic, Mesozoic and Cenozoic eras.
Explain the significance of mass extinctions to the evolution of life.

To earn full credit for this worksheet, you must complete it with a minimum score of 80%. You may re-do the worksheet as many times as you like.

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