Question

How does tracheids and vessels transport water and minerals when they are dead

Answer 1

Plants like ferns and conifers have xylem “straws” that are made of slender cells called tracheids. At maturity these cells die, leaving behind a rigid cell wall scaffolding tube to conduct water and minerals. Flowering plants have an additional type of xylem tissue called a vessel element. Like tracheids, vessel elements are dead at maturity, but unlike tracheids, vessel elements are much wider – more like a smoothie straw! This means that they can transport more water at a faster rate. .

Water molecules move from the soil into living cells of the root, and eventually into the transport cells of the xylem, known as tracheids and vessels. These xylem cells are dead and hollow, allowing rapid water transport. They also have hardened cell walls to help them resist the tendency to collapse as water is sucked through them. Both tracheids and vessels have pits on the sides of their walls, which include porous areas for side-to-side transport. Unlike tracheids, a vessel is composed of many cells stacked end to end, with perforations between cells, allowing for more efficient transport.