Prokaryote Life: Cyanobacteria
A Quick Biology Lesson
An early filamentous prokaryote (Campbell, 1992)
Stromatolites are formed by unicellular organisms called
Cyanobacteria (formally known as blue-green algae).. Cyanobacteria are
Prokaryotes,
which are known to be the earliest forms of life, throughout time they
have adapted to the changing earth, and in turn help it evolve. Prokaryotes
belong to the kingdom Monera (Greek for single) and are small celled
organisms that lack membrane-enclosed organelles. They have
cell walls, but their composition differs from those of plants, protisits
and fungi. They are similar to Eukaryotes, but they have smaller
and simpler genomes, and differ in genetic replication, protein synthesis,
and recombination. Prokaryotes are photosynthetic
and aquatic and can exist in almost any environment, and individually their
impact may be microscopic, but collectively their impact on the earth is
immense. Prokaryotes are divided based on
the differences on how they receive their nutrition (how they obtain energy
and carbon). Cyanobacteria belong to the category termed photoautorophs,
which use light to drive the synthesis of organic compounds from carbon
dioxide.
c) vertical section through layered, unlithified microbial mat; d) Coccoid cyanobacteria
from marine microbial mat; e) Filamentous cyanobacteria (Awramik, 1972)
