Intracellular endosymbionts that originally descended from free-living prokaryotes have been important in the evolution of eukaryotes by giving rise to two cytoplasmic organelles. Mitochondria arose ...

One essential component of each eukaryotic cell is the cytoskeleton. Microtubules, tiny tubes consisting of a protein called tubulin, are part of this skeleton of cells. Cilia and flagella, which are ...