Looking for a Tutor Near You?

Post Learning Requirement »
x

Choose Country Code

x

Direction

x

Ask a Question

x

x
x
For better view click here
x
Hire a Tutor
DISCOVER

Xylem

Loading...

Published in: Biology
20,419 Views

This ppt detailed description of structure and function of Xylem

R. K / Chennai

7 years of teaching experience

Qualification: Pursuing M.Sc.(Botany)

Teaches: Bio Technology, Biology, Botany, EVS, School Level Computer, Zoology, Social Studies, NET

Contact this Tutor
  1. XYLEM STRUCTURE AND FUNCTION KANAGA VALLI.R
  2. INTRODUCTION Plant tissue Meristematic Cells are capable of cell division Simple Tissue composed of a single cell type Permanent Mature cells are incapable of cell division Complex Tissue composed of more than one cell type Epidermis Parenchyma Collenchyma Sclerenchyma Chlorenchyma Xylem Xylem vessels Tracheids Phloem Sieve tubes companion cells
  3. COMPLEX PERMANENT TISSUE Complex permanent tissue consists of a number of dissimilar cells which perform a common function. It forms vascular or conducting tissue in the plant. They are of two types: Xylem Phloem
  4. XYLEM TISSUES Xylem is responsible for conduction of mineral salt and water from roots to upper region and also provides mechanical support to the plant body. Xylem is also called as wood and forms the bulk of roots and stem of vascular plants. Xylem is composed of three types of cells some of which are living and some non-living. sclerenchyma cells (fibers) vessel element with perforations n end walls) tracheids orous cell wall between adjacent tracheids and vessel elements) 00 end walls of adjoining vessel elements have disappeared vessel element porous cell wall between insides of tracheids)
  5. STRUCTURE The vascular tissues are made up of: Xylem vessels - the main conducting cells Xylem tracheids - also conduct water but are not as well adapted as vessels for this function fibres — they have no role in water transport but function in support parenchyma - this acts as packing tissue. aVessels and tracheids are dead cells and they form a system of tubes through which water can travel.
  6. —«ent scUa b ndl Ca b m arenchyma hl
  7. TRACHEARY ELEMENTS These participate in conduction of sap (water and minerals). They are divided into two types — tracheids and vessels. VESSELS: Vessels are elongated tubular structures with a wide lumen. It is formed by a series of cylindrical cells which are joined end-to-end and have perforated walls. The vessels are dead, thick walled and lignified.
  8. XYLEM TRACHEID Tracheids are elongated, thick walled, dead tubular cells with lignified walls. The tracheids are smaller than vessels and form chief conducting element of xylem in gymnosperm and pteridophyte where vessels are absent.
  9. Based on the lignification, tracheids are also classified Annular Spiral Reticulate Sclariform and Pitted
  10. Wood Fibre/ Xylem Fibres They are sclerenchyma fibres. They are distinguished from tracheids on basis of their comparatively thicker walls and obliterated central lumens. These fibres are of two types: libriform fibres have thick cell walls, simple pits and obliterated central lumens XYLEM fibre perforation plates tracheids vessel member pp sp Longitudinal secbon of thestemstmangpri. mary and secondary Figure 8. Detail of Fig. 7 vessel elenmt wifr oblique perforation plate (pp) and scalarv form pvtting (sp) pat. tem. Figure 9, Detail of Fig. 7 showing helically thickened walls (ht) of the smaller vessel elements, prob. ably of metaxylem and xylem parenchyma 01996 Encyclopaedia Britamiu, Inc.
  11. Wood Parenchyma Parenchymatous cells present in the xylem. It is the only living component of the xylem The cells are thin or thick walled with simple pits. These cells store food material in the form of starch or fat.
  12. Xylem can be distinguished into two types on basis of the time of origin and internal structure Protoxylem Metaxylem Protoxylem as the name suggests is the first or easily formed xylem. Metaxylem is formed at a later stage.
  13. How xylem and phloem are formed in the growing plant primary vascular bundle Cambium makes new ri ng of xylem and phloem Cambium grows ci rcumfe renti ally Cambium generates more secondary xylem and phloem Cambium generates a second ring of xylem and phloem
  14. Location of xylem tissue This differs in the stem, leaf and root. Stem: Vascular bundles near the edge of the stem Root: Vascular system in a central position Leaf: Vascular bundles in the midrib and other leaf veins
  15. Ste m Ring aroun
  16. In the root, resistance to the pulling force of the wind epidermis cortex ground pericycle tissues endodermis xylem vascular tissue phloem Figure 3. Cross section of a root
  17. Resistance to tearing in the leaf
  18. Role of xylem Absorbs Water Mineral salts Oxygen Resistance to forces supporting and strengthening Water lost to air Xylem Water moves up xylem @The open ends of xylem vessel cells form complete pipelike tubes. Source Phloem of sugars Sieve cell Companion cell Sink Lateral roots Sugars in the phloem of this carrot plant are moving to sinks.
  19. ????? YOU ?? ALL

Need a Tutor or Coaching Class?

Post an enquiry and get instant responses from qualified and experienced tutors.

Post Requirement

Related PPTs

Upload PPTs

If you have your own PowerPoint Presentations which you think can benefit others, please upload on LearnPick. For each approved PPT you will get 100 Credit Points and 100 Activity Score which will increase your profile visibility.

Upload Now
Home > PowerPoint Slides > Xylem