Question

In which structure did Robert Brown see the cell nucleus?
A. The cell of the orchid root
B. Pollen grains
C. Red blood cells of humans
D. White blood cells of humans

Answer 1

Hint: Robert Brown, a Scottish botanist, while observing the cells from the roots of an orchid, found an opaque region present within the cell. He named this region as the “areola” or the “nucleus”. He described the findings at the Linnean Society of London in 1831 but failed to suggest its function.

Step by step answer:The nucleus was one of the first organelles within the cell to be discovered. The first description of the nucleus was given by Antonie van Leeuwenhoek in his descriptions of the red blood cell of salmon, where he denoted the organelle as the “lumen”.
Then again in1831, Robert Brown, a Scottish botanist, described an opaque structure present within the cell of the orchid as areola or nucleus at the Linnean Society of London in1831. Even though Robert Brown gave a description, he did not suggest a function for the organelle.
Therefore, the correct option is A
Additional information:
The true function of the nucleus was formulated in the early 20th century and was termed the chromosome theory of heredity. Robert Brown is also accredited for the discovery of the Brownian movement which he observed while studying the process of pollination in 1827.
Some other notable works of Robert Brown include a detailed description of cytoplasmic streaming, pollination, fertilization, and numerous taxonomic classification studies. He was also the first to differentiate between gymnosperms and angiosperms.

Note: The description of the nucleus even though given long back by Antonie van Leeuwenhoek, it was Robert Brown who coined the term nucleus. It is important to understand that Antonie van Leeuwenhoek described the nucleus as a lumen in salmon RBC, where unlike human RBC, it possesses a nucleus.