If the xylem of a plant is mechanically blocked, the correct answer is option 2: Transport of water and solutes.

The xylem is responsible for the transport of water and minerals from the roots to the rest of the plant. It is a specialized tissue made up of long, tube-like cells that form a network throughout the plant. The primary function of the xylem is to provide structural support and transport water and dissolved minerals from the roots to the leaves and other parts of the plant. This process is known as transpiration.

However, the xylem is also involved in the movement of some solutes, such as nutrients and hormones, though it is not the main transport pathway for solutes. If the xylem is mechanically blocked, the transport of water and solutes will be affected. This can lead to a lack of water and nutrients reaching the different parts of the plant, causing wilting, stunted growth, and ultimately, the death of the plant.

Transport of gases, on the other hand, is primarily done through the stomata - small openings on the surface of the leaves. Gases such as oxygen and carbon dioxide exchange occur between the plant and the atmosphere through these openings, not through the xylem. Therefore