The experiment in the diagram demonstrates
A.
geotropism
B.
thigmotropism
C.
phototropism
D.
hydrotropism
Correct answer is A
Charles Darwin was one of the first to scientifically document that roots show positive gravitropism and stems show negative gravitropism. That is, roots grow in the direction of gravitational pull (i.e., downward) and stems grow in the opposite direction (i.e., upwards).