The first organism in a food chain is always an?

It is usually a plant. A herbivore or omnivore devours the plant, and a predator eats the herbivore/omnivore, starting and ending a food cycle, also called a food chain. Also, the sun grows the plant in which the animal eats. The first organism in a food chain is a plant or a organism that can photosynthesise. or... There is not a first organism in the food chain! :-)