AP BIOLOGY

Detailed explanation-1: -Damage to the xylem results in a decrease in the flow of water and nutrients throughout the tree. 2. The tree must first start performing photosynthesis in order to make up for the lost nutrients.

Detailed explanation-2: -Injured xylem will carry less water to the branches and leaves. Both of these problems limit the supply of vitally needed water and salts to the leaves. Plants that had little time to prepare for cold temperatures will be more severely injured than those that cooled more slowly.

Detailed explanation-3: -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-4: -Mechanism Driving Water Movement in Plants 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-5: -Water and solutes are transported by the xylem from the roots to the leaves, and food is transported from the leaves to the rest of the plant by the phloem. The process by which water evaporates from the leaves and draws more water from the roots is called ‘transpiration’.