What group of organisms occupies the second trophic level of an ecosystem?

Which codon is the code for the amino acid histidine (his)?

Which of the following statements most accurately describes convergent evolution? the process in which two similar species evolve separately from each other and share similar characteristics the process in which a single species evolves into two or more new species the process in which two entirely different species evolve in response to each other the process in which two different species evolve separately from each other but still share similar characteristics

Diagram of the evolution of land plants?