Short answers, pulled from the story.
Jan Ingenhousz demonstrated that plants require sunlight to revive a mouse trapped under an inverted jar. This experiment revealed the fundamental chemical equation where carbon dioxide and water combine to produce glucose and oxygen.
Oxygenic photosynthesis became significant around two billion years ago during the Paleoproterozoic era. Cyanobacteria produced excess oxygen that eventually oxygenated Earth's atmosphere.
C4 plants like maize achieve leaf photosynthetic rates around 38 to 40 micromoles per square meter per second. These species show no apparent photorespiration compared to C3 types such as cotton or sunflower.
Melvin Calvin won a Nobel Prize in Chemistry in 1961 for this work. He, Andrew Benson, and James Bassham elucidated the carbon reduction cycle using carbon-14 isotopes.
The biochemical capacity to use water evolved once in a common ancestor of extant cyanobacteria between 2450 and 2320 million years ago. This event enabled the evolution of complex life forms requiring oxygen for respiration.