Asked by 2

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

All Answers 1

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

Explanation: oxygen produced by photosynthetic bacteria oxidized dissolved iron in seawater, forming iron oxides (banded iron formations) that settled as ancient "rust" deposits — a key record of rising ocean oxygen.