Who proposed that new cells arise from the division of pre-existing cells?

Briefly describe the contributions of the following scientists in the formulation of the cell theory:
$(a)$ Rudolf Virchow
$(b)$ Schleiden and Schwann

Who coined the term "cell"?

Unicellular organisms are capable of:
$(i)$ Having an independent life.
$(ii)$ Organ development.
$(iii)$ Performing metabolic activities for life.
$(iv)$ Tissue constitution.

Life begins above which level of organization?

$A$ major breakthrough in the studies of cells came with the development of the electron microscope. This is because