Correct answer: B) Gravitropism
Gravitropism is a process of growth by plants in response to gravity pulling it. It is also known as geotropism. There are two type of gravitropism observed in plants positive gravitropism and negative gravitropism.
Positive gravitropism - In this the roots of the plants grow in downward in the direction of gravity.
Negative gravitropism - In negative gravitropism the shoot of the plant grow in upward direction away from the gravity, which is called as negative gravitropism.
It occurs due to presence of plant hormone auxin, which prohibits elongation of cell in the roots which result in the bending of root down in to the soil.
