Write a short note on xylem.
Xylem is complex permanent tissue and is also known as conduction tissues. It consists of tracheids, vessels, xylem parenchyma and xylem fibres. The cells have thick walls, and many of them are dead. Tracheids and vessels are tubular structures. This allows them to transport water and mineral vertically upwards. The parenchyma stores food and helps in the lateral conduction of water. Fibres are mainly supportive in function.