Essentially, Monera is a biological kingdom that is made up of prokaryotes (particularly bacteria). As such, it’s composed of single-celled organisms that lack a true nucleus.
Based on previous classifications, kingdom Monera includes organisms known as Archaea (Archaebacteria) in addition to blue-green algae and Schizopyta (bacteria). However, further studies identified unique characteristics of Archaea that allowed them to be separated and identified as a distinct kingdom.
They are typically unicellular organisms (but one group is mycelial). The genetic material in these organisms is the naked circular DNA. A nuclear envelope is absent. Both, ribosomes and simple chromatophores, are the only subcellular organelles in the cytoplasm.
The predominant mode of nutrition is absorptive but some groups are photosynthetic (holophytic) and chemosynthetic. The organisms are non-motile or move by the beating of simple flagella or by gliding.
Picture Credit : Google
