Question

Answer the following:

What are the salient features of monera?

Answer 1

Salient features of Kingdom Monera:

1. Size: The organisms included in this kingdom are microscopic, unicellular, and prokaryotic.
2. Occurrence: These are omnipresent. They are found in all types of environment which are not generally inhabited by other living beings.
3. Nucleus: These organisms do not have a well-defined nucleus. DNA exists as a simple double-stranded circular single chromosome called a nucleoid. Apart from the nucleoid they often show the presence of extrachromosomal DNA which is a small circular called plasmids.
4. Cell wall: Cell wall is made up of peptidoglycan (also called murein) which is a polymer of sugars and amino acids.
5. Membrane-bound cell organelles: Membrane-bound cell organelles like mitochondria, chloroplast, endoplasmic reticulum are absent. Ribosomes are present, which are smaller in size (the 70S) than in eukaryotic cells.
6. Nutrition: The majority are heterotrophic, parasitic, or saprophytic in nutrition. Few are autotrophic that can be either photoautotrophs or chemoautotrophs.
7. Reproduction: The mode of reproduction is asexual or with the help of binary fission or budding. Very rarely, sexual reproduction occurs by the conjugation method.
8. Examples: Archaebacteria: e.g. Methanobacillus, Thiobacillus, etc. Eubacteria: e.g. Chlorobium, Chromatium, and Cyanobacteria e.g. Nostoc, Azotobacter, etc.