Gravity-induced behaviour of single-celled organisms

Abstract Gravity is the weakest yet most fundamental force in nature, playing a crucial role in sustaining life on Earth. Gravity affects cells and entire organisms. Organisms respond to gravity through either kineses or taxes. Various groups of protozoan organisms are also influenced by gravity. This communication summarises the effects of gravity on microscopic single-celled organisms, particularly on flagellates and ciliates. Gravity-influenced responses in motile microorganisms have also been elucidated, along with the sensory transduction chain and circadian rhythm of gravitaxis.