Question

Nucleus was discovered by
A. Robert Brown
B. Robert Hooke
C. Antonio Philips van Leeuwenhoek
D. Theodor Schwann

Answer 1

Hint:The nucleus was the very first organelle to be discovered. It was first observed as a "lumen", the nucleus, inside the red blood cells of salmon. All other vertebrates still contain nuclei, except mammalian red blood cells.

Complete solution:
Robert Hooke first used the word 'cell' to describe a fundamental unit of life.
Antonie van Leeuwenhoek is the scientist who developed the microscope.
Theodor Schwann gave the cell theory
Antonie Philips van Leeuwenhoek first observed the cell nucleus.
But the nucleus was actually discovered by Robert Brown, was a Scottish botanist who observed it in 1833, and gave it the name the cell nucleus.
The nucleus in a cell is a membrane-bound organelle and it is the information center of the cell. It is found in almost all eukaryotic cells which contain DNA as their genetic material. The nucleus is enclosed by a lipid bilayer known as the nuclear envelope. The double lipid layer is embedded with the nuclear pores. The nucleolus is present inside the nucleus and is the site of ribosome production.

So, the right answer is option A.

Additional Information:
Brown was born on 21 December 1773 in Montrose. He was the son of James Brown, a minister of Scottish Episcopal Church with Jacobite convictions so strong that in 1788 he defied his church's decision to provide allegiance to George III.

Note:In 1827, during examining grains of pollen Clarkia pulchella which was suspended in water under a microscope, minute particles were observed by Brown, now called amyloplasts and spherosomes, ejected from pollen grains which execute the endless jittery motion. The phenomenon is now referred to as the Brownian movement.