This file contains NCERT class 9th complex tissue content detail information about xylem tissue and its components/elements.

1. LIFE
SCIENCES
CLASS - 9
LP - 11 • BITTU KUMAR
• INTEGRATED B.SC. – B.ED.
• LOVELY PROFESSIONAL
UNIVERSITY ,
PHAGWARA,PUNJAB.

3. TOPIC – XYLEM

5. CHARACTERISTICS OF
XYLEM

6. XYLEM ?
Nature. Xylem (Gr. xylos = wood) is a vascular and mechanical tissue.
In other words, it is a conducting tissue.

7. ELEMENTS ARE OF FOUR
DIFFERENT TYPES:
1. Tracheid's;
2. Vessels or tracheae;
3. Xylem parenchyma and
4.Xylem sclerenchyma (or fibre).

8. FILL IN THE BLANKS
The main function of xylem is to carry
__________ and
mineral salts upward from ________ to
different parts of shoots.

9. CHARACTERISTICS
Single celled
End walls remain intact
Walls –thick
Lumen - narrow

10. FUNCTION
Conduction of water through capillary action.

11. MCQ
WHICH OF FOLLOWING IS NOT A CHARECTERISTIC OF TRACHEIDS.
A. MADE UP OF A ROW OF CELLS
B. END WALLS REMAIN INTACT.
C. CELL WALLS ARE VERY THICK
D. NARROW LUMEN

13. VESSELS
Made up of a row of cells.
End (= transverse) walls gets dissolved and become perforated.
The walls of vessels are less thick, and they have a wider lumen.

14. HOW PITS ARE FORMED IN VESSELS
?
No lignin is laid down where plasmodesmata were present in
the original cell walls. These non-lignified areas are known as
pits and they allow water to pass sideways between one xylem
vessel and the next.
As vessels and tracheids of xylem have the lignified cell
walls, so, this simply mean that these cells are hollow and there
are no cell contents to restrict the flow of water.

15. IDENTIFY VESSELS AND
TRACHEIDS

16. COMPARISON
Tracheid Vessel
1. Single celled. Made up of a row of cells.
2. The end walls remain intact. End (= transverse) walls gets
dissolved and become
perforated.
3. The walls of tracheids are
very thick with a narrow lumen.
The walls of vessels are less
thick and they have a wider
lumen.

17. RECPITULATION
Components of xylem is known as____________.
Name the elements of xylem.
Tracheids are having _________cell wall and ________lumen.
Vessels are single celled (TRUE/FALSE)

18. HOMEWORK
1. What are different types of elements of xylem tissue?
2. Tabulate the difference between tracheid and vessels.
3. Draw the diagram of tracheid and vessels.
4. ACTIVITY-
Take a stem along with some leaves or flower,
Dip step in coloured water for few hours ,place the setup in sunlight
Cut the thin circular transverse section of stem for slide preparation.