Which statements describe hydrotropism? Check all that apply. Hydrotropism is a plant’s response to light. Hydrotropism is a plant’s response to an external stimulus. Hydrotropism causes cells to grow longer on one side of the roots. Hydrotropism causes cells to grow longer on one side of the stems. Hydrotropism causes a plant to grow toward light. Hydrotropism causes a plant to grow away from light.