nucleus

The nucleus is the centre of a cell. It is the most important part of the cell because it contains the cell's DNA. DNA is the genetic material that determines the cell's structure and function.

The nucleus is surrounded by a membrane called the nuclear envelope. The nuclear envelope controls what goes in and out of the nucleus.

Inside the nucleus, there are chromosomes. Chromosomes are made up of DNA and proteins. They contain the genes that control the cell's activities.

The nucleus is important for cell growth, division, and reproduction. It also controls the cell's metabolism.

The word "nucleus" is related to the words "kernel" and "nut.".