Do all cells have a nuclei?

No.All cells do not necessarily have a nucleus. Cells with a defined nucleus are called eukaryotic cells, while cells possessing no nucleus are called prokaryotic cells.Eukaryotic cells have a defined nucleus. read more

Eukaryotic cells have a defined nucleus, otherwise called the "brain" of the cell. This nucleus is surrounded by a membrane which separates the nucleus from the other clearly defined parts of the cell, called organelles. Examples of organelles are mitochondria and chloroplasts. read more

All nucleated cells have a nucleus, all aneucleate cells do not. By definition, eukaryotic cells have a "true nucleus," though certain cells in multicellular organisms may lose their nucleus as they develop to maturity, most notable being erythrocytes, a.k.a. mature red blood cells. read more

Most eukaryotic cell types usually have a single nucleus, but some have no nuclei, while others have several. This can result from normal development, as in the maturation of mammalian red blood cells, or from faulty cell division. read more