Transport of Nutrients
Angiosperms have a vascular system that transport water and nutrients throughout the plant. Like the blood vessels in animals, the vascular system of plants provides a pathway for important nutrients and water to move from one part of the plant body to another. The vascular system has vascular tissue in the form of xylem and phloem.
Xylem is a transport subsystem that carries water upward from the roots to every part of a plant. The two main conductors are the tracheids and vessel elements. Tracheids are hollow cells with thick cell walls that resist pressure. They allow water to move through a plant more efficiently. Vessels elements are much wider and larger than tracheids. The vessels elements transform into a tube, moving water more freely. Tracheids and vessels elements also help to support the structure of the plant body.
Xylem is a transport subsystem that carries water upward from the roots to every part of a plant. The two main conductors are the tracheids and vessel elements. Tracheids are hollow cells with thick cell walls that resist pressure. They allow water to move through a plant more efficiently. Vessels elements are much wider and larger than tracheids. The vessels elements transform into a tube, moving water more freely. Tracheids and vessels elements also help to support the structure of the plant body.
Angiosperms have a second transport subsystem composed of vascular tissue called phloem. Phloem transports solutions of nutrients and carbohydrates produced during photosynthesis from the leaves to the rest of the plant, where the energy is used for growth and maintenance. It is composed of sieve tube elements and companion cells. These cells have pores that allow sugars and materials to move between them. Sieve tube members contain cells called companion cells that help them function.