How Do Many Animal Endosymbionts Grow?

Question

How do many animal endosymbionts grow? 
A) on the surface of the host 
B) on low nutrients 
C) by reducing iron oxide 
D) on inorganic minerals 
E) in biofilms

Accepted Answer

Many animal endosymbionts grow in biofilms, which are communities of microorganisms that attach to a surface and produce a protective extracellular matrix. This allows them to access nutrients and resources from the surrounding environment while also protecting them from host immune responses.