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: -German scientists Theodore Schwann and Mattias Schleiden studied cells of animals and plants respectively. These scientists identified key differences between the two cell types and put forth the idea that cells were the fundamental units of both plants and animals.

Detailed explanation-3: -Schleiden preferred to study plant structure under the microscope. As a professor of botany at the University of Jena, he wrote Contributions to our Knowledge of Phytogenesis (1838), in which he stated that all plants are composed of cells.

Detailed explanation-4: -Matthias Schleiden proposed that all animals are made up of cells.

Detailed explanation-5: -The classical cell theory was proposed by Theodor Schwann in 1839.