Question

In which Kingdom, would you classify the archaea and nitrogen-fixing organisms, if the five-kingdom system of classification is used?
A)Plantae
B)Fungi
C)Protista
D)Monera

Answer 1

Hint: It is a kingdom of single-celled organisms with prokaryotic cell organization means they have no nuclear membrane. They usually contain 70s ribosomes and reproduce asexually by binary fission and budding. They are also considered as environmental decomposers.

Complete answer:
Classification of Kingdom Monera into three sub-kingdoms i.e Archaebacteria, Eubacteria, and Cyanobacteria.
Archaebacteria- it includes all the archaea, and they are a primitive type of prokaryotes.these are the most ancient bacteria and mainly found in the most extreme habitats such as halophiles in salty areas, thermoacidophiles in hot springs, and methanogens in marshy areas.
-Their cell wall structure is different from other bacterias which help them to survive in extremely harsh conditions. Their mode of nutrition is autotrophic and the nucleotide sequence of archaebacteria is tRNA and rRNA which is unique.
Eubacteria- this group consists of nitrogen-fixing bacteria. Eubacteria are also known as true bacteria. The cell wall of eubacteria is rigid and mainly made up of peptidoglycan. Eubacteria locomotion with the help of flagella.there are few bacterias which contain short appendages on the cell surface known as the Pili which help the bacteria during sexual reproduction and it also helps a pathogen to attach to the host.
-The eubacteria are divided into gram-positive bacteria and gram-negative bacteria depending upon the nature of the cell wall and the stain. Examples of two eubacteria are rhizobium and clostridium.

Additional Information:Cyanobacteria- it is also known as the blue-green algae. They are photosynthetic in nature because they contain chlorophyll, carotenoids, and phycobilins. They are mostly found in aquatic reasons and some are even used to fix atmospheric nitrogen. Examples of cyanobacteria are Anabaena spirulina nostoc etc.
Plantae- it comprises all the plants. This Kingdom comprises organisms that are eukaryotic, multicellular, and autotrophs.their cell wall is rigid and they have chloroplast and chlorophyll pigment which is required for photosynthesis.
Fungi- it includes microorganisms such as yeast and molds and mushrooms. They are a group of eukaryotic organisms.
The Protista- this Kingdom comprises eukaryotic organisms. They are neither animals nor plants or fungi.they are generally unicellular organisms and found as a colony of cells. They mostly live in water or damp terrestrial environments. They also live as parasites.
So, the correct answer is,” Monera”.

Note: -Monera helps enrich the soil and also serves as a very important part of the nitrogen cycle. So, they are very useful organisms.
-They also help in the making of some food items and antibiotics. Some monerans that are methanogens play a very important role in the treatment of sewage wastes.
-Many organisms depend on the archaebacteria for their food.