Q. Explain the structure and the functions of the nucleus.
Ans. Nucleus is the largest cell organelle. Most of the cells have single nucleus. It is spherical or oval in shape. It is surrounded by double membrane called nuclear membrane and contains a colourless, dense fluid called nucleoplasm. In nucleoplasm, some spherical bodies are embedded called nucleoli.
In nucleoplasm, some thread-like structures form a network called chromatin network. These thread-like structures are called chromosomes. These chromosomes carry genes which are responsible for hereditary characters. Since, nucleus controls all the vital activities of the cell so it is also called control centre of the cell.