AP Bio History of Life on Earth Video 2

During the Archean Eon, the oceans were full of

• dissolved oxygen and carbon dioxide.

• solid rock and sediment.

• frozen ice and glaciers.

• dissolved iron and minerals.

During the Archean Eon, the oceans were green because

• high levels of oxygen in the atmosphere.

• the absence of life forms in the oceans.

• the presence of blue algae.

• the presence of dissolved iron and sulfur producing bacteria.

During the Archean Eon, the atmosphere was mostly nitrogen along with

• phosphorus, chlorine, and helium.

• methane, ammonia, and carbon dioxide.

• carbon monoxide, argon, and neon.

• oxygen, hydrogen, and sulfur.

The Archean ocean went from green to red because

• The increase in dissolved iron and oxygen oxidation.
• The presence of large marine animals changed the color.
• The ocean was filled with volcanic ash.
• The ocean was affected by meteor impacts.

As photosynthetic organisms increased, the levels of carbon dioxide in the atmosphere decreased. This caused the planet to

• remain unchanged and support fewer species.

• heat up and reduce biodiversity.

• increase carbon dioxide and promote deserts.

• cool down and support diverse ecosystems.