Question

Cell theory was proposed by?
1. Schleiden and Schwann
2. Robert Brown
3. Leeuwenhoek
4. Rudolf Virchow 

Answer 1

Correct Answer - Option 1 : Schleiden and Schwann

Explanation:

The cell theory was proposed by Schleiden and Schwann.

• Matthias Schleiden was a German botanist who examined a large number of plants and observed that all plants are composed of different kinds of cells that form the tissues of the plant.
• Theodore Schwann was a British Zoologist who studied different types of animal cells and reported that cells had a thin outer layer which is today known as the plasma membrane’. He also concluded, based on his studies on plant tissues, that the presence of a cell wall is a unique character of the plant cells.
• Schleiden and Schwann together formulated the cell theory.

• Rudolf Virchow gave the concept of Omnis cellula - e - cellula which means new cells arise from the pre-existing cells. 
• He modified the hypothesis of Schleiden and Schwann to give the cell theory a final shape. Cell theory as understood today is:

1. All living organisms are composed of cells and products of cells.
2. All cells arise from pre-existing cells.

• Robert Brown, a British Biologist discovered the nucleus in the year 1831.
• Anton van Leeuwenhoek discovered the first living cell in 1674. Algae Spirogyra was the first living cell observed under a microscope by him.