up vote 3 down vote accepted. $\pi$ is the name of the constant relating the diameter and circumferance of a circle. It's a definition, a particular constant that we thought deserved a name. $e$ happens to be the name of a constant from a particular limit. Like $\pi$, we named it because we thought it would be useful. In Physics, many, many constants have names. Gravitational constants, expansional constants, electrical constants, etc. Each is useful, but somewhat arbitrarily chosen.
Bacteria: The Monera Kingdom Bacteria are classified into two groups: Eubacteria (true bacteria) and Archaebacteria (Ancient Bacteria). They are autotrophic. 28-1 Chapter 28: Microbiology. 28-2 Viruses Viruses are noncellular, nonliving particles and therefore are not included in the classification scheme.
Eubacteria The domain that comprises the single kingdom Bacteria, containing the true bacteria. There are 11 main groups: purple (photosynthetic), Gram-positive, cyanobacteria, green non-sulphur, spirochaetes, flavobacteria, green sulphur, Planctomyces, Chlamydiales, Deinococci, and Thermatogales.ubacteria A kingdom (or subkingdom) of prokaryotic organisms that comprise present-day bacteria. They include aerobic and anaerobic species and occur in virtually all habitats. Some live in or on the bodies of other organisms, and may cause disease.