OBJECTIVE FORESTRY

Detailed explanation-1: -There are two types of “transport” tissues in plants-xylem and phloem. 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.

Detailed explanation-2: -Unlike in the phloem, where substances can move both up and down the plant, the xylem only transports water and mineral ions up the plant from the roots to the leaves and flowers and any other organs that might require them.

Detailed explanation-3: -Once water is in the xylem, it travels upwards-against the force of gravity-towards the rest of the plant. Water is able to move against gravity due to two forces: tension and cohesion. Tension is a ‘sucking force’ which is created when water evaporates from leaves (transpiration), pulling more water into the leaf.

Detailed explanation-4: -Xylem transports water in plants. Water is absorbed from the soil through root hair cells. Water moves by osmosis from root cell to root cell until it reaches the xylem. It is transported through the xylem vessels up the stem to the leaves.