15 points come and ! which characteristic describes all bacteria? a rod-shaped b microscopic c multicellular d autotrophic

Ans is option B, microscopic.

All bacteria are microscopic i.e. they can not be seen with naked eyes.They are single celled organisms with a size ranging from 0.2 to 10 microns.

Only a few bacteria are rod shaped (bacillus) like Escherichia coli. Others may be coccus (spherical), spiral and vibrio i.e. comma shaped.

Bacteria may be either autotrophic or heterotrophic in nature. Most of the bacteria are heterotrophic in nature. Heterotrophic bacteria cannot synthesize  their own food because they lack chloroplast. So, they are dependent on other organisms to obtain their food.  Autotrophic bacteria on the other hand can synthesize their own food because they have chloroplast.

Example of heterotrophic bacteria is helicobacter pylori.

 Example of autotrophic bacteria is cyanobacteria.

D

Explanation:

because like cyanobacteria they make their own food.