Which of the following is true Based on the nature of stimuli, tropism can be classified as follows
1. Phototropism: Movement of a plant part towards light. e.g. shoot of a plant.
2. Geotropism: Movement of a plant in response to gravity. e.g. root of a plant.
3. Hydrotropism: Movement of a plant or part of a plant towards water. e.g. root of a plant.
4. Thigmotropism: Movement of a plant part due to touch. e.g. climbing vines.
5. Chemotropism: Movement of a part of plant in response to chemicals. e.g. growth of a pollen tube in response to sugar present on the stigma