Which of the following is a major evolutionary step that is hypothesized to have occurred in the evolution of photosynthesis?
A)the acquisition by cyanobacteria of a second photosystem.
B)the ability to use water as an electron donor
C)the acquisition by eukaryotic organisms of photosynthesis by endosymbiosis
D)All three of these steps are hypothesized to have been important in the evolution of photosynthesis.

Question

Quizplus · Accepted Answer

Each of the options listed represents a significant evolutionary development in the history of photosynthesis. A) The acquisition of a second photosystem allowed for the splitting of water molecules and the release of oxygen, a critical step in the evolution of oxygenic photosynthesis. B) The ability to use water as an electron donor is directly related to the evolution of oxygenic photosynthesis, which dramatically altered Earth's atmosphere and allowed for the evolution of aerobic life. C) The acquisition of photosynthesis by eukaryotic organisms through endosymbiosis (the incorporation of photosynthetic cyanobacteria to form chloroplasts) was crucial for the evolution of plants and the spread of photosynthesis across various ecosystems.

Which of the Following Is a Major Evolutionary Step That