parasitic

definition: 
(Of an organism) living as a parasite: (be parasitic on)
sentence: 
Mistletoe is parasitic on trees. Since viruses are parasitic on cellular life, the first life could not have been anything like a virus. Nevertheless, growing these parasitic plants in vitro is difficult, because of their dependence on a connection to hosts for normal development, and because of their specific germination requirements.
difficulty: 
easy
toefl frequency: 
2
toefl classification: