Explain that algae and plants produced oxygen by photosynthesis.

In the subtopic How oxygen increased, this learning objective focuses on explain that algae and plants produced oxygen by photosynthesis. Within The composition and evolution of the Earth's atmosphere, students should explain this idea in the exact curriculum context rather than as an isolated fact. Approved keywords for this objective include oxygen, photosynthesis, algae, and plants. photosynthesis means the process by which algae and plants convert carbon dioxide and water into glucose and oxygen using sunlight. Avoid students often confuse the process of photosynthesis with respiration, thinking that plants only consume oxygen; instead remember that photosynthesis is the process by which algae and plants produce oxygen using carbon dioxide and sunlight. For exam answers, when you see a diagram of gas exchange, calculate the ratio of O₂ produced to CO₂ consumed. A ratio close to 1:1 indicates photosynthesis by algae or plants.