frumur

Frumur are the basic structural and functional units of all living organisms, responsible for metabolism, growth and reproduction. The study of cells is called cell biology. In multicellular organisms, cells form tissues and organs; some organisms consist of a single cell.

Frumur are broadly categorized into prokaryotic and eukaryotic. Prokaryotic cells, found in bacteria and archaea, lack a defined nucleus and most membrane-bound organelles, with DNA freely in the cytoplasm. Eukaryotic cells, which include plants, animals, fungi and protists, have a true nucleus containing DNA and a system of organelles such as mitochondria, endoplasmic reticulum and Golgi apparatus. Plant and algal cells also contain chloroplasts for photosynthesis and a cell wall.

A cell is bounded by a plasma membrane that controls traffic between the interior and the environment. The cytoplasm contains cytosol and organelles, including ribosomes where proteins are synthesized. The cell contains genetic material carried on DNA, organized into chromosomes.

Cells reproduce by division. In mitosis, a somatic cell divides to produce two genetically identical daughter cells. In meiosis, germ cells divide to form gametes with half the chromosome number. The cell cycle describes growth and replication, with checkpoints that regulate progression.

Many cells are specialized for specific functions, such as neurons for signal transmission, muscle cells for contraction, or guard cells in plant leaves. Stem cells can differentiate into multiple cell types, providing a basis for development and regenerative research.

Frumur underpin biology and medicine: understanding their structure and function informs everything from development to disease and biotechnological applications.