Which of the following organisms belongs to the Kingdom Monera?

Colourless,unicellular,cell wall bound,spherical or rod-shaped micro-organism and lacking organized nucleus is called:

Biochemical similarities are used in the identification of which of the following?

The given characters are seen in which of the following group?
$(i)$ Unicellular,colonial,filamentous,symbiotic or free living.
$(ii)$ The colonies are surrounded by a gelatinous sheath.
$(iii)$ Some can fix atmospheric nitrogen in specialized cells called heterocysts.
$(iv)$ They often form blooms in water bodies.

Cyanobacteria are –

True nucleus is absent in