Question

1. Fill in the table below regarding the role of the three tissue systems in plants. (feel free to reorganize as it makes sense to you – but make sure you hit all terms and questions)

Tissue system	Cells/tissues	Function	Primary/Secondary Growth or both?	In what plants?	Other
Dermal	Epidermis				Cuticle Trichomes Stomata
	Periderm
Ground	Parenchyma
	Collenchyma
	Sclerenchyma
Vascular	Xylem Tracheids Vessel Elements
	Phloem Sieve tube members

Answer 1

Dermal tissues

On the basis of function meristems are decided into protoderm ( epidermis) and periderm

Protoderm produces epidermis of stem and leaves while as periderm forms cortex and endodermis.

These are present in plants

Ground tissue: are those which have lost the capacity to decide and have attained a permanent shape and size

Parenchyma: simple tissue made up of isodiametric living cells having thin smooth cellulose walls. The tissue takes part in storage of food, conduction and Turgidity.

Collenchyma: It is simple permanent tissue made up of isodiametric and elongated cells having unevenly distributed pectocellulosic nonlignified cell walls . Collenchyma provides both mechanical support and elasticity allowing plant organs to grow in size. The tissue is found in hypodermis of dicot stem and petioles.

Sclerenchyma: is a simple permanent tissue which is usually formed of dead, highly thick walled cells, with pointed or oblique cell walls . The fibres occur in sheets and bundles and consists of chief mechanical tissue because they bear compression, bending, shearing and pull. These are found in hypodermis of monocot stems, vascular bundles, Pericycle.

Complex permanent tissue are xylem and phloem

They are those permanent tissues which are made up of more than one type of cells that cordainate their activities to perform similar function e.g conducting tissues.

Xylem: are complex permanent tissue conduct sap and water. It provides mechanical strength It is made up of tracheids, vessels, xylem fibres and xylem parenchyma.

Tracheida are elongated dead tube like cells with wide lumen and lignified walls.

Xylem occurs in all vascular plants I.e pteridophytes, gymnosperm s and angiosperms.

Phloem: phloem or bast is a complex permanent tissue which conducts organic food in the plant body. It has four compnets sieve tube, companion cells, phloem parenchyma and phloem fibres.