A citizen, who voluntary self-identifies as a party member, functions as the smallest unit of the party organization.
Species
dscd
mohawk
Interacting With Other Species
organ, or unit e.g. a flower Population
The cell is the level of organization that is the smallest unit of life. Cells working together make tissues.
The smallest unit of ecological organization is an individual organism. This could be a single plant or animal that interacts with its living and non-living environment within a specific ecosystem.
field
cell The Cell is the smallest metabolically functional unit of life.1 1. http://en.wikipedia.org/wiki/Cell
The smallest unit is a quark. I'm not sure what you mean by 'of classification'
If it is a molecular compound, the smallest unit is called a molecule. If it is an ionic compound, the smallest unit is called a formula unit.