German zoologist who claimed that all animals are made of cells?

Answer 1

The cell theory was first publicly expounded by two men -- Mathias Schleiden and Theodor Schwann -- and they proposed that ALL living things were not only MADE of cells but CAME FROM cells. They were the first people to expound internationally what is known today as the ''Cell Theory'' but they were not necessarily the first zoologists or botanists to consider the idea. Quite a few scientists earlier in the 19th century were pretty sure that this was the case, but they kept the idea to themselves, hence Schleiden and Schwann got the credit.

The cell theory as they visualized it, contains their contention that the cell is the smallest form of life. That may be true, but they knew nothing of viruses, and their position in the biological world depends on subjective evaluations. Most medical personnel seem to be of the opinion that viruses are alive, whereas the world of biological science does not generally accept this. Viruses are able to do none of the things that living organisms (and cells) do.

Personally, I would suggest that viruses belong in a kind of philosophical ''Twilight Zone'' between things that are clearly alive, and things that are clearly not alive. The whole issue is further complicated by the sudden appearance in the world of biological science of the PRION.

That is a real,and entirely different problem.

Answer 2

Theodor Schwann

Answer 3

theadore schwann