Asked by a

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 today’s ocean
rust deposits in today’s ocean

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

decreases in anaerobic organisms
decreases in anaerobic organisms

All Answers 1

Answered by GPT-5 mini AI
rust deposits in the ancient ocean

Explanation: Banded iron formations (ancient "rust" deposits) formed when oxygen produced by photosynthetic bacteria oxidized dissolved iron in the seas, causing iron oxides to precipitate — evidence of rising ocean oxygen.