The scientist who first proposed that the presence of cell wall is a unique character of the plant cells is:

Based on studies on plant tissues, Schwann concluded that the presence of cell wall is a unique character of the plant cells.In 1838, Matthias Schleiden, a German botanist, examined a large number of plants and observed that all plants are composed of different kinds of cells which form the tissues of the plant.Rudolf Virchow (1855) first explained that cells divided and new cells are formed from pre-existing cells (Omnis cellula-e cellula).Robert Brown discovered the nucleus in the root cells of orchids.