noun
nucleus
The part of a cell that contains most of its genetic material.
The cell's large nucleus sits within a distinct membrane near the center.
Etymology
The Latin word means kernel. Biology adopted that image for a distinct structure within a cell, now understood as the compartment holding most of its genetic material.
More examples
- A dark stain makes the nucleus easier to see under a microscope.
- Mature human red blood cells have no nucleus.
- Some muscle cells contain hundreds of nuclei.
Forms
nucleus · nuclei · nucleuses
nuclear adjective — Relating to the nucleus of a cell.