The correct answer is A. Hooke.
Robert Hooke was an English physicist, architect, physiologist, and inventor who is best known for his work on microscopy. In 1665, he published Micrographia, a book in which he described his observations of various objects using a microscope. In one of his observations, he saw a thin slice of cork and noticed that it was made up of tiny, box-like structures. He called these structures “cells” because they reminded him of the cells in a monastery. Hooke’s discovery of cells was a major breakthrough in the field of biology. It paved the way for the development of cell theory, which states that all living things are made up of cells.
The other options are incorrect.
- B. Schleiden was a German botanist who is considered one of the founders of cell theory. He proposed that all plants are made up of cells.
- C. Oken was a German naturalist who proposed that all animals are made up of cells.
- D. Darwin was an English naturalist who is best known for his theory of evolution. He did not discover cells.