Which kingdom incorporates photoautotrophs,chemoautotrophs and heterotrophs?

The thermal tolerance of thermophilic blue-green algae is due to:

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.

Chemosynthetic autotrophic bacteria like $Nitrosomonas$ obtain energy from $........$ for their $\text{ATP}$ production.

Organisms that obtain energy by the oxidation of reduced inorganic compounds are called .....

Gas vacuoles are found in which of the following?