Diversity In Living Organisms — Science STD 9 — Question

Kingdom Monera is the first of the five kingdoms of biological classification. It comprised most organisms with a prokaryotic cell organization. For this reason the kingdom was sometimes called Prokaryota or Prokaryotae. Prior to its creation these were treated as two separate divisions of plants: The Schizomycetes (bacteria) were considered fungi, and the Cyanophyta were considered blue-green algae. The latter are now considered a group of bacteria, typically called the cyanobacteria.

Monera has been divided into Archaea and Bacteria, forming the more recent six-kingdom system and three-domain system. All new schemes abandon the Monera and now treat the Bacteria, Archaea and Eukarya as separate domains or kingdoms. To sum up:

1. Kingdom Monera are one-celled without an organized nucleus. Examples: bacteria and blue-green "algae."
2. They have existed on earth longer and are more widely distributed than any other organisms.
3. They are found in almost every imaginable habitat; in air, soil, and water and in extreme temperatures and harsh chemical environments.
4. Their one distinguishing characteristic is that there are no membrane bound "organelles".
5. Pre dominant mode of nutrition is absorption but some may be photosynthetic or chemosynthetic.
6. Reproduction by asexual method.
7. True mitotic cell division absent.