Definition: A taxon is Critically Endangered when the best available evidence indicates that it meets
any of the criteria A to E for Critically Endangered, and it is therefore considered to be facing an extremely high risk of extinction in the wild
Definition: one of three metabolic pathways for carbon fixation in photosynthesis, along with C4 and CAM. This process converts carbon dioxide and ribulose bisphosphate (RuBP, a 5-carbon sugar) into 3-phosphoglycerate through the following reaction:
CO2 + H2O + RuBP → (2) 3-phosphoglycerate
This reaction occurs in all plants as the first step of the Calvin–Benson cycle.