kjerner

Kjerner is the plural of kjerne, a Norwegian noun with several related meanings. It denotes the central part or core of something and is used both literally and figuratively. In everyday speech, kjernen is the essential part of an issue, as in kjernen i problemet.

In biology and related sciences, kjerne often refers to the nucleus of a cell, usually called cellekjerne in full form; the cell nucleus contains DNA and regulates cellular activities. When speaking of many cells, one might refer to cellekjerner; in physics, atomkjerner denote atomic nuclei—protons and neutrons bound in the center of an atom.

In botany and food contexts, kjerne designates a seed or pit inside a fruit or nut, such as eplekjerne (apple core) or solsikkekjerne (sunflower seed). These kernels can be edible or discarded, depending on the plant.

In computing and mathematics, kjerne is used for kernel: the central part of an operating system (Linux-kjernen) or the kernel of a function or a map in mathematics. Kernel concepts also appear in statistics and signal processing as kernel functions in density estimation and filtering.

The term also features in compound forms that describe central or essential groups, such as kjernefamilie (nuclear family) or kjerne av en organisasjon (the core of an organization).