Question

World's smallest cell

Answer 1

mycoplasma is the worlds smallest cell

Answer 2

The Mycoplasma is the world’s smallest cell.

The very smallest organisms discovered on globe are determined based on different factors of the organism size that includes the genome size, height, mass, length and volume.  

It is now possible than even smallest organisms are  undiscovered.

Along with this, there are few debates over the life definition.