Earth's Past

Which of the following is the correct order of ages in geologic time?

How do scientist think that early atmosphere was probably formed?

Volcanic "outgassings" provided sources of

Modern day atmosphere has approximately what percentage of the air is Oxygen ?

Where do scientist thing the water from the oceans came from?

Pangea was the first supercontinent on Earth.

Precambrian shields are made of deformed metamorphic rocks.

Which of the following is a defining characteristic that all protobionts had in common?

The graph illustrates the change in oxygen concentration that occurred around 2.3 billion years ago. Which of the events listed below most likely led to this rapid rise in atmospheric oxygen?

Which molecule did cyanobacteria add to the atmosphere?

the chemical process in which Carbon dioxide and Water combine, using energy from the Sun, to make Sugar and Oxygen

The evolution of cyanobacteria led to which event in Earth's history?

Choose the answer that represents the correct sequence of events in the origin of life.

I. formation of protobionts

II. synthesis of organic compounds

III. evolution of prokaryotes

IV. evolution of eukaryotes

True or False. Eukaryotes evolved before prokaryotes, which explains why prokaryotes contain mitochondria and chloroplasts with DNA.

Which of the following is the strongest evidence that prokaryotes evolved before eukaryotes?

Which types of organisms developed first due to the early environmental conditions on Earth?