nucleus, cell nucleus, karyon

a part of the cell containing DNA and RNA and responsible for growth and reproduction

• pronucleus — the nucleus of the ovum or sperm after fertilization but before they fuse to form the nucleus of the zygote

• organelle, cell organ — a specialized part of a cell; analogous to an organ

• nucleoplasm, karyoplasm — the protoplasm that constitutes the nucleus of a cell

• nucleolus, nucleole — a small round body of protein in a cell nucleus; nucleoli contain RNA and are involved in protein synthesis
• chromatin — the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins
• achromatin — the part of a cell nucleus that is relatively uncolored by stains or dyes
• chromosome — a threadlike body in the cell nucleus that carries the genes in a linear order

• cell — the basic structural and functional unit of all organisms; cells may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and animals