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There are two types of permanent tissues in plants.

1. Simple permanent tissues

(made up of only one type of cells).

These include:

Name of tissue

Structure

Occurrence

Function

Parenchyma

- Cells living.

- Spherical in shape.

- Nucleus present.

- Thin cellulose wall.

- Intermolecular spaces 

  present.

Cortex of root,

Mesophyll of leaf,

Ground tissue of stem.

Storage of food (eg. Potato).

Temporary support.

Collenchyma

- Cells living.

- Nucleus present.

- Elongated in shape.

- Unevenly thickened 

   with cellulose at  

   corners.

- Little intercellular

  space.

Below epidermis of stem,

Leaf stalks.

Flexibility and support to leaves and stem.

Mechanical support.

Sclerenchyma

- Cells are dead.

- Nucleus absent.

- Elongated and narrow.

- Lignin deposition.

- Reduced lumen.

- Vacuole absent.

 

Hard covering of seeds,

In stems around vascular bundles.

Mechanical strength and support to the plant.

 

 

2. Complex permanent tissues

(made up of different types of cells)

These include:

a. Xylem:

  • It forms the main mechanical tissue in the form of wood.
  • It consists of tracheids, vessels, xylem fibres and xylem parenchyma.
  • It conducts water and minerals from roots to other parts of the plant.

b. Phloem:

  • It consists of sieve cells, sieve tubes, companion cells, phloem parenchyma and phloem fibres.
  • It conducts organic solutes from storage parts to other regions.
  • It conducts food from the leaves to other non-green parts of the plant.

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