Living things that are sensitive to gravity are said to be geotropic.
Selection for geotropic root elongation rate in alfalfa under field conditions.
geotropic in Science
(jē-ŏt'rə-pĭz'əm) The directional growth of an organism in response to gravity. Roots display positive geotropism when they grow downwards, while shoots display negative geotropism when they grow upwards. Also called gravitropism.