Summary
Vascular tissue made of dead cells that carries water and minerals upward from roots.
In depth
Vessels and tracheids have lignified walls (spirals, rings, pits) that withstand tension. No end walls in vessels. Transport is unidirectional and passive, driven by transpiration pull and root pressure.
Water movement is passive in dead xylem cells. The continuous, narrow vessels support cohesion, and pits allow lateral movement. Cavitation can block vessels but plants refill or bypass them.
Key idea: xylem transports water upward only, from roots to leaves.
Frequently asked questions
What is Xylem?
Vascular tissue made of dead cells that carries water and minerals upward from roots.
Which area of biology covers Xylem, and how advanced is it?
Xylem is one of the 56 topics in Plant Biology. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Cohesion-Tension Theory, Phloem, Plant Kingdom.
Can you give an example of Xylem?
Lignin gives wood its strength.
What should I learn before Xylem?
Xylem is a Beginner topic, so no earlier topic is required. Other Beginner topics in Plant Biology that pair well with it include Plant Kingdom, Photosynthesis, Chlorophyll.
What topics are related to Xylem?
The closest topics to Xylem are Cohesion-Tension Theory, Phloem, Plant Kingdom, Plant Tissues. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Xylem?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Xylem. To practise the whole of Plant Biology, use the Plant Biology quiz.
How is Xylem different from Cohesion-Tension Theory?
Xylem: Vascular tissue made of dead cells that carries water and minerals upward from roots. Cohesion-Tension Theory: Water molecules stick together and to xylem walls, so evaporation tension pulls a continuous water column up. Read both side by side and note what each one explains.
How should I study Xylem step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Cohesion-Tension Theory and explain the difference aloud. Finally, take the Plant Biology quiz and come back to this page for any question you miss.