Question

Name the process by which bacteria multiply themselves?

Answer 1

Binary fission.

Explanation:

Bacteria being a prokaryote divide by a binary fission which is sort of asexual reproduction.
This process is bit similar to mitosis that occur in eukaryotic cells. Breifly: in this process first bacterium replicate its DNA, then the cell elongates and the genetic materials(original and copied one) move towards opposite poles of cell and consequently, the cell membrane pinches in the centre and the two bacteria having their individual cell's components are formed.

http://biology-pictures.blogspot.com/2011/11/binary-fission-in-bacteria.html