Which statement describes an interaction that helps maintain the ecosystem?
A. The frogs make energy available to this ecosystem thi
B. The algae directly provide food for both the rotifers an
C. The green-backed heron provides energy for the mos
D. The catfish population helps control the populations of

You are given an electron micrograph of a bacterial cell. in the micrograph you can clearly see three thin layers of different densities surrounding the cell. based on the micrograph, you can infer that this cell is and would appear after application of the gram stain procedure. gram-negative / pink gram-positive / purple gram-positive / pink gram-negative / purple