geotropism is caused by
The answer is: the plant's response to Earth's center of gravity.
Geotropism is a type of tropism, or directional growth response, caused by the force of gravity acting on the plant. It is defined as an organism's response to gravity, and is usually observed in plants. In dicotyledonous plants, when seedling cells become contained in the seed, they respond to gravity by growing roots downward and stems upward. This response is called geotropism and is caused by the abundance of water that accumulates in the lower part of the plant. Geographic orientation plays an important role in the growth and development of plants, helping them orient themselves in relation to their environment. Thigmotropism and haptic tropism are two other types of tropism that also help plants orient themselves in response to their environment.
