Respiration and Transportation in Organisms - Transportation of Water and Minerals in Plants
Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Plants absorb water and minerals from the soil through roots. The roots have root hairs that increase the surface area of the root for the absorption of and mineral nutrients dissolved in water.
The transport of water and nutrients in plants is carried out by a pipe-like vascular tissue called the Xylem. The xylem forms a continuous network of channels that connects roots to the leaves through the stem and branches.
Water and minerals are transported upwards from the roots to all parts of the plant through the xylem vessel.
Transpiration is the process of evaporation of water molecules from the surface of the leaves through small pores called stomata.
The evaporation of water from leaves creates a suction pull (similar to the suction produced when drinking through a straw) called the Transpiration Pull, which can pull water to great heights in tall trees.
Transpiration also helps in cooling the plant, preventing it from overheating in direct sunlight.
📐Formulae
💡Examples
Problem 1:
Explain the role of root hairs in the absorption of water.
Solution:
Root hairs are outgrowths from the epidermal cells of the root. They increase the surface area of the root available for the absorption of and minerals.
Explanation:
By increasing the surface area, root hairs ensure a greater contact with the water present between the soil particles, facilitating efficient absorption via osmosis.
Problem 2:
How does water reach the leaves of a tall Eucalyptus tree against gravity?
Solution:
Water reaches the leaves through the xylem due to the Transpiration Pull.
Explanation:
As water evaporates from the stomata in the leaves via transpiration, it creates a negative pressure or suction force. This force pulls the column of from the roots through the xylem vessels all the way to the top of the tree.