The concept that new cells arise from pre-existing cells was proposed by whom?

What could the cell theory proposed by Schleiden and Schwann not explain?

What is the meaning of the phrase '$Omnis$ $cellula-e-cellula$'?

Select the statements which are related to Schwann.
$(i)$ He reported that cells have a thin outer layer which is today known as plasma membrane.
$(ii)$ Cell wall is a unique character of the plant cell.
$(iii)$ Body of plants and animals are composed of cells and products of cells.

Match the following:

Column-$I$	Column-$II$
$A$. Schleiden	$1$. Nucleus
$B$. Schwann	$2$. German botanist
$C$. Robert Brown	$3$. Living cell
$D$. Leeuwenhoek	$4$. British Zoologist

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