The appearance of eukaryotic cells made it possible <span>for more complex, multicellular organisms to exist. The difference between the eukaryotic cells and the </span> prokaryotic<span> cells (bacteria and archaea) is the </span>membrane-bound organelles, the nucleus, which contains the genetic material. The <span>eukaryotes cells are responsible for forming multi-cellular organisms, which consist of many kinds of </span>tissue<span> made up of different </span>cell types<span>.</span>
In biology, evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection. The theory of evolution is based on the idea that all species? are related and gradually change over time.
