AP BIOLOGY

Detailed explanation-1: –In 1831, while researching the fertilization processes of plants in the families of the Orchidaceae and Asclepiadaceae, he noted the existence of a structure within orchid cells, and so many other plants, that he called the cell’s “nucleus.” Thus, the correct answer is option (B) Robert Brown.

Detailed explanation-2: -The nucleus was discovered by Robert Brown. He found an opaque area in plant cells and named it Nucleus.

Detailed explanation-3: -He recognised and described the existence of the cell nucleus and stomata (breathing pores that act as gateways, in order to exchange gases with the atmosphere). The Linnean Society are the caretakers of Brown’s microscope, as restored by Prof Brian J Ford, on which his theory of Brownian motion was discovered.

Detailed explanation-4: -In 1831, while investigating the fertilization mechanisms of plants in the Orchidaceae and Asclepiadaceae families, he noted the existence of a structure within the cells of orchids, as well as many other plants, that he termed the “nucleus” of the cell.

Detailed explanation-5: -Brown published his research findings and gave speeches. His discovery of the nucleus and its role helped to put together the cell theory, which states that all living organisms are composed of cells, and cells come from pre-existing cells. Brown’s discovery helped to confirm the second half of the cell theory.