presentation 03 - plant tissues

TissuesTissuesan integrated group of cells with a

common structure and function

Plant TissuesPlant Tissues1. Meristematic tissue: rapid cell division,

lengthening of shoots and roots

2. Dermal tissue: covering for the plant body

3. Ground tissue: support, photosynthesis, and storage

4. Vascular tissue: conduction of water, food, and dissolved minerals; strengthens and supports the plant

Meristematic TissueMeristematic Tissue cells that do not

differentiate cells retain the ability to

divide Types:

Apical – primary growth at root and shoot tips

Lateral – secondary growth in trees and shrubs

Intercalary – secondary growth in monocot stems

Apical meristemApical meristem In shoot tips and

root tips Allium cepa root tip

Root cap

Apical meristem

Region of cell differentiation/maturation

Region of cell elongation

Region of cell division

Dermal TissuesDermal Tissues Single layer of cells called the

epidermis in herbaceous plants Guard cells Trichomes Root hairs

Functions Absorption Secretion of cuticle Protection Control of gas exchange

Epidermis

Cuticle

The Ground The Ground Tissue SystemTissue System

Parenchyma cellsParenchyma cells spherical-shaped cells found throughout plant thin primary walls living, metabolizing tissue functions:

Photosynthesis & respiration Storage (starch, oil droplets,

water, and salts) Wound healing & regeneration

CollenchymaCollenchyma beneath the epidermis in

young stems and in large veins of leaves

elongated cells that have unevenly thickened cell walls

alive at maturity flexible support system found uniformly throughout

the plant

SclerenchymaSclerenchyma structural support two types:

fibers – support in wood, bark, leaves, stems

sclereids – protection in fruits, seeds, other plant organs

primary and secondary cell walls.

dead at functional maturity

The Vascular The Vascular Tissue SystemTissue System

Complex Complex Vascular Vascular TissuesTissues

Xylem Conducts water and dissolved

minerals from the roots

Phloem Conducts dissolved food

materials, carbohydrates, in solution

Continuous throughout plant

Support plant body

All 4 types of tissues are present

in the root tip

Young dicot stem Young monocot stem