Which organisms can be found at the first, or lowest, trophic level?

What are the possible blood types among the children of parents that are ab and ii? oa) types a and b ob) types a, b, and ab c) types a, b, and o od) types a, b, ab, and o

The bacteria inside a tube worm would be analogous to what organism in the ocean ecosystem near the waters surface? a. photosynthetic algae b. shrimp c. clown fish d. parasitic lamprey

What is the most common structure of volcanoes?