How can an organism be in more than one trophic level in an ecosystem?

Food webs largely define ecosystems, and the trophic levels define the position of organisms within the webs. But these trophic levels are not always simple integers, because organisms often feed at more than one trophic level. For example, some carnivores also eat plants, and some plants are carnivores.

hope it helps..

Explanation:

"do a testcross with a homozygous recessive plant."