Which is an abiotic component of a marine ecosystem?
a) coral reef
b) detritus on the bottom of the ocean
c) fish in the water column
d) sand on the ocean floor

explanation:

option b detritus on the bottom of the ocean

answer; earthquake;

an informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.