SUPPORTING TISSUES IN PLANTSHow is support provided for in Herbaceous and woody plants?
TYPES OF SUPPORTING TISSUESIN PLANTS
FUNCTIONS OF THE PARENCHYMA
WOOD OR THE XYLEM TISSUES
What are the Xylem tissues?
Plants generally, are knows to possesses supporting tissues which gives them definite shape, strength, rigidity and resistance against external forces such as wind and water to which they are continuously subjected.
TYPES OF SUPPORTING TISSUES IN PLANTSThe main supporting tissues in plants are PARENCHYMA, COLLENCHYMA, SCLERENCHYMA (FIBRE), AND WOOD=XYLEM.
The structure of some of these tissues are practically not the same
PARENCHYMA TISSUESWhere is the parenchyma found or located?
The parenchyma tissues are found in the cortex of stem, phloem, root, leaf, mesophyll, storage tissues and the xylem
STRUCTIURE OF THE MESOPHYLLThe mesophylls are composed of cells with large vacuoles and relatively thin wall. They are mainly living cells with cellulose and many air spaces within them. Parenchyma tissues are the most common and in abundant of plants tissues
FUNCTIONS OF THE PARENCHYMA
The functions of the parenchyma are as follows
i. When the vacuoles are filled with sap, parenchyma tissues gives firmness and turgidity to the stem of herbaceous plants
ii. The parenchyma can also store food and water
iii. They are found in the leaf and mesophyll, functioning mainly in the synthesis of food.
COLLENCHYMAWhat is Collenchyma?
Collenchyma cell are usually located in the Cortex of stem, root and in the Hypodermis just beneath the epidermis
THE COLLENCHYMA STRUCTURE
The cells of collenchyma tissues are living, elongated and unevenly thickened at the corners. The cells are flexible thus allow the bending and twisting strains to which the stem, roots and the leaves of plants are often subjected to
THE FUNCTIONS OF A COLLENCHYMAWhat are the functions of a Collenchyma?
i. Collenchyma cells provides strength and supports in young growing plants parts such as the stem, petioles and leaf blade
ii. The Collenchyma cells gives flexibility and resilience to the plant.
iii. They also enable the plant to bend without breaking
SCERENCHYMAWhat is Sclerenchyma?
Sclerenchyma cells are found mainly in the pericycle, in the vascular tissues cortices of stem and roots.
The structure of the Sclerenchyma cells is that they have thicken walls containing lignin in addition to cellulose and other substances
There are two types of Sclerenchyma,they are
i. FIBRES AND
1. Fibres are elongated cells with tapering ends. These help to provide strength and flexibility to plants
2. Sclereids unlike fibres, are not too elongated but have great strength like the fibres too.
The functions of SclerenchymaThe functions of Sclerenchyma are as follows
i. The Sclerenchyma fibre type give flexibility to plants and prevent them braking up easily
ii. Sclerenchyma provide strength, rigidity, hardness and support to plants
WOOD OR THE XYLEM TISSUESWhat are the Xylem tissues?
Then wood or Xylem tissues are mainly in the vascular tissues of stems, roots and leaves
The structure of the wood or Xylem tissues is made up of many cells. They are
iii. Fibres and
iv. Xylem parenchyma
TRACHEIDS:Tracheids are non-living elongated, tapering cells with thickened, lignified walls which have piths that aids the passage of water and helps to dissolve mineral salts.
ii. VESSELS: Vessels are long tabular structures that are formed by the fusion of several elongated cells places or stacked one upon another
iii. FIBRES: fibres are similar to the Sclerenchyma fibres. They are narrow, elongated cells with very thick walls and tapering end walls
XYLEM PARENCHYMA:these are similar to the parenchyma tissues. They are composed of cells with large vacuoles. The functions of the Xylem parenchyma tissues are as follows
1. The Xylem tissues provides support, strength and shape to the plant.
2. Xylem parenchyma is also a conducting tissue as it helps to conduct water and dissolve mineral salts from the roots to the leaves.
PHLOEM TISSUESThe phloem tissues are closely associated with the major supporting tissues. The tissues are located within the vascular bundles of all plants, be it in the roots, stems or leaves
The structure of the Phloem tissues are made up of four cells. These are sieve tubes, Phloem parenchyma, companion cells and Phloem fibres
SIEVE TUBES:these are made up of elongated rows of cylindrical cells arranged vertically. The cells are living and mainly conducts food
PHLOEM PARENCHYMA:these are similar to the parenchyma cells earlier discussed. They provides strength and support to the plant. The cells also helps in food storage