NEET BIOLOGY

Detailed explanation-1: -Plants respond directly to Earth’s gravitational attraction, and also to light. Stems grow upward, or away from the center of Earth, and towards light. Roots grow downward, or towards the center of Earth, and away from light. These responses to external stimuli are called tropisms.

Detailed explanation-2: -Hydrotropism. The movement or the growth of a plant in relation to the stimulus of water is called hydrotropic movements and the equivalent response to the stimulus of water is called hydrotropism. In this type of movement, roots show the positive hydrotropic response, as they move and grow towards the water.

Detailed explanation-3: -The Role of Transpiration Pull in Plants This results in upward pull of water from the root to the mesophyll cells by generating a negative pressure in xylem vessels to pull the water from the soil. Transpiration pull in plants results from the evaporation or excretion of water from the surface of cells in the leaves.

Detailed explanation-4: -Final answer: Transpiration pull will be maximum if the stomata are open, the atmosphere is dry, and the soil is moist.