Figure 21-1 Use the Figure to Answer the Corresponding Question(s)

Q2: Describe the four requirements for chemical evolution

Q3: Organisms whose metabolic processes are harmed by

Q4: Experiments called in vitro evolution or directed

Q5: Some protobionts have been shown to have

Q6: The time in the history of Earth

Q9: MATCHING<br>Match the period with the biological events<br>a.Cambrian

Q10: The Mesozoic era is often called the

Q11: One of the most significant steps in

Q12: The first land animals were probably the:<br>A)

Q16: The first cells were most likely heterotrophic