Exam 12: Earths Evolution Through Geologic Time

The first bacteria probably used ________ instead of water as a source of hydrogen.

________ are the dominant land plants of the Cenozoic era.

Much of the original free oxygen in the atmosphere combined with iron dissolved in water to become iron oxide.

Human ancestors developed the tendency to walk on two legs instead of four in order to accommodate ________.

What group of animals were the first to leave the ocean to become the first amphibians?

The largest mass extinction in the Phanerozoic occurred in the ________.

The Goldilocks scenario suggests that ________.

Following the reptilian extinctions at the close of the Mesozoic era,two groups of mammals,the marsupials and ________,evolved and expanded.

Volcanic activity was common in western North America during much of Cenozoic time.

The major adaptions that made it possible for mammals to evolve into their modern forms included all of the following except ________.

The ________ were the dominant trees of the Mesozoic era.

The major source of oxygen in Earth's atmosphere is from the decay of plants.

Trilobites brachiopods fish dinosaurs

Human evolution takes place during the ________ period of the ________ era.