AP BIOLOGY

Detailed explanation-1: -The bulk of water absorbed and transported through plants is moved by negative pressure generated by the evaporation of water from the leaves (i.e., transpiration)-this process is commonly referred to as the Cohesion-Tension (C-T) mechanism.

Detailed explanation-2: -As transpiration occurs, it deepens the meniscus of water in the leaf, creating negative pressure (also called tension or suction). The tension created by transpiration “pulls” water in the plant xylem, drawing the water upward in much the same way that you draw water upward when you suck on a straw.

Detailed explanation-3: -Plants release water vapor into the atmosphere, which creates a negative pressure in the xylem, the layer of small vessels that brings water up from the root. If a plant has enough water, it opens its stoma, the pores under its leaves, to pull in carbon dioxide, which it photosynthesizes into sugar to fuel growth.

Detailed explanation-4: -The water eventually is released to the atmosphere as vapor via the plant’s stomata-tiny, closeable, pore-like structures on the surfaces of leaves. Overall, this uptake of water at the roots, transport of water through plant tissues, and release of vapor by leaves is known as transpiration.

Detailed explanation-5: -Therefore, a positive p (compression) increases total, while a negative p (tension) decreases total. Positive pressure inside cells is contained by the cell wall, producing turgor pressure in a plant. Turgor pressure ensures that a plant can maintain its shape.