Cellene

Cellene is the Norwegian term for cells, the basic structural and functional units of living organisms. Cells are the smallest units capable of independent life and form tissues and organs in multicellular organisms, from bacteria to humans. They share common features such as a surrounding membrane, cytoplasm, and genetic material that directs their activities.

There are two major cell types: prokaryotic and eukaryotic. Prokaryotic cells, found in bacteria and archaea, lack a membrane-bound nucleus and most organelles. Eukaryotic cells, in animals, plants, fungi, and protists, contain a nucleus and numerous organelles, including mitochondria and endoplasmic reticulum.

Structural components include the cell membrane, cytoplasm, nucleus (in eukaryotes), and organelles such as mitochondria, ribosomes, Golgi apparatus, and, in plants and some algae, chloroplasts and a cell wall. These components coordinate metabolism, growth, and responses to the environment.

Cells reproduce by division: mitosis for most body cells and meiosis for reproductive cells in eukaryotes. Bacteria reproduce by binary fission. Cell theory, established in the 19th century by Schleiden, Schwann, and Virchow, posits that all organisms are composed of cells, that the cell is the basic unit of life, and that new cells arise from existing ones.

Modern cell biology studies cellular processes, signaling, gene expression, and interactions using microscopy, biochemistry, and molecular biology, with implications across medicine, genetics, and biotechnology.