Question

T. Schwann and M. Schleiden were
A. Dutch biologists
B. English biologists
C. Austrian biologists
D. German biologists

Answer 1

The cell theory is a scientific theory that now has great acceptance universally. This theory proposed that living organisms are composed of cells which are the basic structural/organizational unit of all organisms and that all cells come from pre-existing cells. Cells are also the basic unit of reproduction.

Complete answer:
The cell theory was proposed by two scientists who are Theodor Schwann and Matthias Jakob Schleiden. Schleiden proposed that every structural part of a plant consists of cells or the result of cells. He also forwarded the theory that these cells were formed by a crystallization process either within other cells or from the outside. In the same year, Theodor Schwann proposed that along with the plants, animals are also made up of cells or the product of cells in their structures. This was remarked as a major achievement in the field of biology about the structure of animals and plants. The postulates of the cell theory are as follows:
Firstly, all living organisms are made up of one or more cells. Secondly, the cell is the most basic unit of life. And the third one is all cells arise only from pre-existing cells.
Both of these two scientists who proposed the cell theory are German biologists.
Theodor Schwann was born on December 7, 1810, in the city of Prussia, Germany, and died on January 11, 1882, in Germany. He was a physiologist who studied at the Jesuits’ College at Cologne and later attended the University of Bonn and then the University of Wurzburg, where he started his studies of medical science. In 1834, after graduating with a medical degree from the University of Berlin, he started to assist a renowned physiologist Johannes Peter Muller.
Matthias Jakob Schleiden was born on April 5, 1804, in the city of Hamburg, Germany, and died on June 23, 1881, in Frankfurt, Germany. He was a botanist. Schleiden took his education at Heidelberg during the period of 1824–27 and he started to practice law in Hamburg. But soon he realized his keen interest in botany.

Hence, the correct answer is option (D).

Note: The cell theory was proposed in the year 1839 by two German biologists and they are Theodor Schwann and Matthias Jakob Schleiden. At first, Schleiden proposed his theory on the plants and said a plant consisted of cells or the result of cells. Further, Theodor Schwann said that along with the plants, animals are also made up of cells or the product of cells in their structures.