Yes.
Mostly. Because most are transparent (and need to be dyed to really be seen).
Bacteria can be seen with an ordinary light microscope.
Because Viruses are very small... Even smaller than bacteria... They are so small that they cannot be seen by any ordinary light microscope ! hence You Need To Use An Electron Microscope!
a microscope because the bacteria is so small
yes
None.
Bacteria is the smallest thing that can be seen using a microscope.
Yes, bacteria can be seen under a light microscope as they are larger than viruses. However, viruses are much smaller and cannot be seen with a light microscope. Specialized electron microscopes are required to visualize viruses.
Generally viruses are smaller than bacteria, which are themselves smaller than animal and plant cells. Therefore D is the smallest and is least likely to be visible using an ordinary microscope. See related links for an interactive scale of cells, from the macroscopic to the microscopic, down to a single carbon atom.
Many people were involved. Since bacteria were easily seen with a microscope, they were studied first. Viruses were not seen until the electron microscope but it was know that somethings were causing disease that were not bacteria. Antony van Leeuwenhoek was the first to describe bacteria.
Bacteria are the smallest of microorganisms that are visible under a light microscope. A light microscope can see things as small as 0.2 micrometres!
Any organism that is too small to be seen by the naked eye must be seen through a microscope. These small organisms are called microorganisms. Bacteria and spermatozoa are examples of microorganisms that we can only view through a microscope.
Viruses were too small to be seen in a microscope so they were not identified till the 1930s.