Question

which answer option best describes the benefit to early photosynthetic organisms gained by having two different photosystems in one cell? they produced oxygen. they could use water as an electron donor and reduce co₂. they could thrive in places where there was little or almost no light. these organisms produced carbohydrates at twice the rate of organisms with a single photosystem.

Explanation:

Early photosynthetic organisms with two photosystems could use water as an electron - donor in the light - dependent reactions and then use the energy and reducing power generated to reduce CO₂ in the Calvin cycle. Producing oxygen is a by - product of using water as an electron donor. Thriving in low - light places is not the main benefit of having two photosystems. There is no evidence that they produce carbohydrates at twice the rate just because of two photosystems.

Answer:

They could use water as an electron donor and reduce CO₂.