All they need for their living is carbondioxide in air ,water and some nutrients .so basically their roots are responsible for collection of water which contains life giving nutrients .but we take food as a solid substance which hasto be converted into energy
An organism's trophic level refers to the food chain position that it occupies. Producers always occupy the Trophy level 1, Primary Consumer occupies the Trophy level 2, Secondary Consumer has the Trophy level 3 and the Tertiary level fills in the Trophy level 4.
To understand the environment of the fossilized organism to see what it would have ate or drank anything. in the surrounding area.