Some thought they were shadows of undiscovered planets crossing the Sun, while others believed they were dark clouds in the Sun's atmosphere. The movement of sunspots across the face of the Sun allowed astronomers in the early 1600's to make the first estimates of the Sun's rotation period (about 27 days).
Answer;
-Viruses are too small to be seen in a light microscope, however viruses can be seen with an electron microscope with 100,000x magnification
Explanation;
-Viruses are considerably smaller, as they are merely nucleic acid surrounded by a protein shell as opposed to an entire living cell. Viruses typically range from 20-400 nm, meaning one needs an electron microscope to see them.
Bacteria are over 100 times larger than viruses, but both can still only be seen by using a microscope. However, bacteria can be seen through a light microscope while virus can not. (since the maximum magnification of a light microscope is x1500 which is not enough to view a virus).
A bacterial atp lets protons into the cytoplasm using them ( bacteria & protons ) using them to make atp.
<span>So, though they don't have mitochondria, </span>bacteria<span> can </span>generate<span> energy through glycolysis and by generating a proton gradient across their cell membranes</span>