Who was the German botanist among the following?

Which scientist proposed that the presence of a cell wall is a unique character of plant cells?

................examined a large number of .................and observed that all are composed of different kinds of cells which form the tissues.

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

What is the smallest structural and functional unit of a living organism?

The living component of the cell was termed by $Dujardin$ as: