AP BIOLOGY

Detailed explanation-1: -Matthias Jacob Schleiden was a German botanist who, with Theodor Schwann, cofounded the cell theory . In 1838 Schleiden defined the cell as the basic unit of plant structure, and a year later Schwann defined the cell as the basic unit of animal structure.

Detailed explanation-2: -In 1838, Matthias Schleiden, a German botanist, concluded that all plant tissues are composed of cells and that an embryonic plant arose from a single cell. He declared that the cell is the basic building block of all plant matter. This statement of Schleiden was the first generalizations concerning cells.

Detailed explanation-3: -Schleiden studied cells as the common element among all plants and animals. Schleiden contributed to the field of embryology through his introduction of the Zeiss microscope lens and via his work with cells and cell theory as an organizing principle of biology. Schleiden was born in Hamburg, Germany, on 5 April 1804.

Detailed explanation-4: -Hence answer is ‘German biologists’