Reptiles Dominated The

Q19: The approximate age of the Earth is:<br>A)

Q20: The mass extinction at the end of

Q21: Cyanobacteria can be found in columns of

Q22: Figure 21-1<br>Use the figure to answer the

Q24: Great swamp forests covered the globe and

Q25: MATCHING<br>Match the period with the biological events<br>a.Cambrian

Q26: The first cells were autrophs,

Q27: There is evidence that life existed about:<br>A)

Q46: Clay is considered a possible site for

Q70: Briefly explain the iron-sulfur world hypothesis and