Prokaryotic cells are single cells that evolved before eukaryotes, which are organisms whose cells contain nuclei and organelles. A prokaryotic cell has no true nucleus or membrane-bound structures called organelles. Pro... More »

An organelle is a unique part of a cell that has a specific function. The term is a combination of the word "organum," which means instrument or engine, and the suffix "-elle," which means small. More »

Eukaryotic cells have organelles, membrane-bound structures that perform different functions in the cell, and prokaryotic cells do not. Some typical eukaryotic organelles include the nucleus, mitochondria, ribosomes, Gol... More »

Eukaryotic cells are advanced cells that have, at minimum, a cellular membrane surrounding cytoplasm, a cytoskeleton and membrane-covered organelles. More advanced eukaryotic cells also contain a nucleus that protects ge... More » Science Biology Cells

Animal cells have many distinct characteristics when compared to plant cells, including their varied shapes, their many types of organelles, their centrioles, cilia and lysosomes, and their cell-to-cell junctions. Animal... More »

Organisms whose cells lack nuclei are called prokaryotic cells or prokaryotic organisms. They differ from organisms called eukaryotic, which have nuclei in most of their cells. More »

Cells are considered the smallest unit of life because they are the smallest components in living things, and some organisms, such as bacteria, are made up of single cells. In addition, each part of the animal body, incl... More »