qelizat

Qelizat (the Albanian term for cells) are the basic structural and functional units of all known life. They are the smallest units that can carry out the processes characteristic of living organisms and form the building blocks of all organisms, from unicellular microbes to complex multicellular plants and animals. In biology, qelizat are categorized into two broad types: prokaryotic and eukaryotic. Prokaryotic cells, found in bacteria and archaea, lack a membrane-bound nucleus and most other internal compartments. Eukaryotic cells, which make up plants, animals, fungi, and many protists, contain a defined nucleus and numerous membrane-bound organelles.

Common features across cells include a plasma membrane that encloses the cell, a cytoplasm with cytosol, and genetic material. In eukaryotes, the nucleus houses DNA, and organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus support metabolism and protein processing. Plant and algal cells typically include chloroplasts for photosynthesis and a rigid cell wall, while bacterial cells have cell walls with peptidoglycan. Ribosomes carry out protein synthesis, and the cytoskeleton provides structural support and enables movement.

Cells perform essential life processes, including metabolism, energy conversion, growth, and reproduction. Prokaryotes reproduce mainly by binary fission, whereas eukaryotes use mitosis (and meiosis for sexual reproduction). The cell theory states that all living organisms are composed of one or more cells, the cell is the basic unit of life, and new cells arise from preexisting cells.