The formation of $Akinetes$ occurs in ..........

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

The given figure shows the structure of filamentous blue-green algae,Nostoc,with a structure marked as $X$. Select the option which shows the correct identification of $X$ with its feature.

Which of the following is considered the most primitive?

In $Nostoc$,the heterocysts are:

Bacteria are considered as plants,because