The mode of nutrition in bacteria is .......

Some hyperthermophilic organisms that grow in highly acidic habitats are divided into two groups,which are called:

Assertion: Chemosynthesis is an autotrophic nutrition.
Reason: Chemoautotrophs contain chlorophyll pigments.

Assertion $A$: Bacillus and Coccus types of bacteria are found in colonial forms.
Reason $R$: In bacteria,cells formed by cell division remain surrounded by a secreted mucilaginous substance.
Which option is correct for Assertion $A$ and Reason $R$?

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

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.