Answer:
Thigmotropism is a plant's response to touch.
Thigmotropism is a plant's response to an external stimulus.
Thigmotropism can occur quickly or slowly.
Thigmotropism may involve the way in which a plant grows.
Thigmotropism may involve the closing and opening of plant leaves.
note:
Gymnosperms possess several key evolutionary innovations compared to earlier groups such as the clubmosses and ferns. They produce sperm-containing pollen, which is carried through the air by the wind to the female. This innovation has freed these plants from the need for water for sexual reproduction.
