When the walls of the excavations are to be kept vertical and in order to protect the safety of. workmen, the general public, this or other work or structures, or excavation walls, or pipe. installation including ma terials encountered in the excavation which have a tendency to slough.
Hierarchy of Living Things. Biological organization, or the hierarchy of life, is the hierarchy of complex biological structures and system that define life using a reductionistic approach. The traditional hierarchy, as detailed below, extends from atoms (or lower) to biospheres.
What is the Three-Domain System? The three-domain system is a way for classifying biological organisms. This classification system distinguishes between eukaryotic organisms, organisms which have cells which include a nucleus, and two types of prokaryotic organisms, organisms with cells which lack a nucleus.