question_answer 40)

  Cell arises from pre-existing cell was stated by (a) Haeckel                         (b) Virchow                        (c) Hooke                            (d) Schleiden

Answer:

  (b) In 1938 Schleiden proposed the idea that plants consist of cells. Later in the year 1839, Schwann independently asserted that all animals and plants are made up of cells. This joint finding forms the basis of cell theory. The cell theory was refined further in 1855,  when R, Virchow presented the idea that all cells arise from pre-existing cell. His amorphism was (Omnis Cellula-e-Cellula).