Question

32. An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to a. make life on land difficult for aerobic organisms. b. change the atmosphere from oxidizing to reducing. c. make it easier to maintain reduced molecules. d. cause iron in ocean water and terrestrial rocks to rust (oxidize). e. prevent the formation of an ozone layer.

Answer 1

d. cause iron in ocean water and terrestrial rocks to rust (oxidize)

Explanation:

The Great Oxygenation Event (GOE) refers to the introduction of huge amounts of free oxygen into the atmosphere. This phenomenon was caused by photosynthetic cyanobacteria during the Paleoproterozoic, i.e., 2.5–2.2 billion years ago. During this period, oxidized iron minerals appeared in the soil and also were deposited on the deep ocean floor due to reactions with oxygen in the seawater from oceans. Moreover, during the Devonian (approximately 410- 360 million years ago), land plants greened the continents and it had brought higher levels of atmospheric oxygen, thereby increasing the amount of oxidized iron in the soil and rocks.