Answer:
Been brought about by the cell theory announced by Theodor Schwann and Matthias Schleiden in 1838, whereby cells were held to be the basic units of all living tissues. Improvements in the microscope during the 19th century made it possible gradually to lay bare the basic structures of cells.
Explanation:
A mass movement is movements of masses of bodies of soil, bed rock, rock, debris, soil etc. which usually occur along steep-sided hills and mountains because of the pull of gravity
