Question

Cyanobacteria are classified under_______________
(a)Protista
(b)Plantae
(c)Monera
(d)Algae

Answer 1

Hint: Cyanobacteria being prokaryotes lack organelles like mitochondria, lysosomes, plastids, goggle bodies, endoplasmic reticulum, centrosome, etc. It is a free living photosynthetic organism. It is responsible for algal bloom and produces potent toxin.

Complete answer:
Kingdom Monera includes prokaryotic organisms which have unicellular organisms. Cyanobacteria are a group of photosynthetic bacteria, some being nitrogen-fixing bacteria like Nostoc, hence belonging to the Kingdom Monera.

Additional Information:
-Monera is a Greek word meaning ‘single’ or ‘solitary’ and was first proposed as a phylum by Ernst Haeckel.
-Bacterias contain 70S ribosomes.
-The Monerans reproduce asexually by binary fission or budding and show autotrophic, parasitic, heterotrophic type of nutrition.
-Flagella in the locomotory organ for most of the bacteria. The arrangement and number of flagella may be different among different species of bacteria, like monotrichous, lophotrichous, amphitrichous, or peritrichous.
-Bacteria possess different shapes like cocci (spherical or oval-shaped), bacilli (rod-shaped), vibrios (comma-shaped), spirillum (spiral or coiled shaped), filament (filaments like fungal mycelia), stalked or budded (swollen at places).
-Archaebacteria are the most ancient bacteria found in the most extreme and harsh habitats such as salty areas (halophiles), hot springs (thermoacidophiles), and marshy areas (methanogens).
-Eubacteria are known as ‘true bacteria’. They are divided into two categories- gram-positive and gram-negative.
So, the correct answer is, ‘ Monera.’

Note:
-Kingdom Monera under the three-domain system of taxonomy by Carl Woese in 1977 was divided into two domains, Archaebacteria, and Eubacteria.
-Kingdom Monera has the oldest known microorganisms on earth.
-The cell wall is rigid and made up of peptidoglycan.
-Bacteria are often environmental decomposers and are also the cause of the disease in plants and animals.