Select the right option which relates to Schwann regarding the following statement 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 product of cells Choose the correct option from below
a)	All are incorrect	b)	Only III is correct	c)	All are correct	d)	II and III are correct

(c)

Schwan (1839), a British Zoologist, studies different types of animal cells and reported that cells had a thin outer layer. Which is today known as the ‘plasma membrane’.

Based on his studies on plant tissues, he also concluded that the presence of a cell wall is a unique character of the plant cells. On the basis of this, Schwann proposed the hypothesis that the bodies of animals and plants are composed of cells and its products.

Schleiden and Schwann together formulated the cell theory. This theory however, did not explain as to how new cells were formed. Rudolf Virchow (1855) first explained that cells gets divided and new cells are formed from pre-existing cells (Omnis cellula-e-cellula).

He modified the hypothesis of Schleiden and Schwann to give the cell theory a final shape. Cell theory as understood today is

(i) All living organism are composed of cells and products of cells

(ii) All cells arise from pre-existing cells