plant tissues

PLANT TISSUES

Plants have organs which are composed of different tissues, which in turn are composed of cells of different types. A tissue is a group of cells with a common function, structure or both. An organ consists of several types of tissues that together carry out particular function.

DIFFERENT PLANT CELLS

A flowering plant has the ability to grow its entire life because it possesses meristermatic (embryonic) tissues. The apical meristems are located at or near the tips of stem and roots, where they increase the length of their structure by means of mitosis. This increase in length is called primary growth.

Monocots also have an intercalary meristem; this allows them to regrow lost parts.

The apical meristem produces three types of meristems and these are develop into the three types of specialized primary tissues in the body of the plant:

·         Protoderm gives rise to the epidermis

·         Ground meristem gives rise to ground tissue

·          Procambrium gives rise to vascular tissue

 STRUCTURE AND FUNCTION OF SPECIALIZED PLANT TISSUES OF EPIDERMIS

EPIDERMIS

A. EPIDERMAL TISSUE 

EXAMPLE OF AN EPIDERMAL TISSUE

 STRUCTURE

It is a single layer of closely packed, flat, brick shaped cells with a large vacuole. Then Ariel parts of the plant are covered with a cuticle.

 FUNCTION

The cuticle minimizes water loss (because it has cutin) and protects the plant against bacteria

B. ROOT HAIRS

EXAMPLE OF A ROOT HAIR

STRUCTURE

They are specialized epidermal cells of the roots. Unicellular outgrowth of the epidermal cell.

FUCTION

Increase the surface area of the root for absorption of water and minerals. it also anchor the plant.

C.TRICHOMES (STERM AND LEAVES HAIR)

TRICHOMES

STRUCTURE

It is a specialized epidermal cell of stems and leaves. Multicellular outgrowth of the stem and leaves. 

FUNCTION

Protects the plant from sun and conserve moisture. Protects plants and from herbivores, produce toxic substances.

 D. STOMATA

stomata

STRUCTURE

Specialized epidermal cells called guard cells, which are bean shaped, enclosed an opening called a stoma pore. The guard cells contain a nucleus and chloroplast. It has a thick inner membrane. Woody plants have lenticels.

FUNCTION

Transpiration and gaseous exchange take place through the stomata

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