What evidence is there that oxygen levels in the sea increased due to photosynthetic bacteria?(1 point)

Responses

global cooling
global cooling

rust deposits in the ancient ocean
rust deposits in the ancient ocean

rust deposits in today’s ocean
rust deposits in today’s ocean

decreases in anaerobic organisms

1 answer

The evidence that oxygen levels in the sea increased due to photosynthetic bacteria is best represented by rust deposits in the ancient ocean. This is because the presence of iron oxide (rust) in sedimentary deposits indicates that free oxygen was available in the ocean, which is a result of photosynthesis by cyanobacteria. These organisms produced oxygen as a byproduct, leading to the Great Oxidation Event.