[bio] 04 - Plant Tissues Crisologo

Tissues an integrated group of cells with a common structure and function

Plant Tissues 1.

2.

3.

4.

Meristematic tissue: rapid cell division, lengthening of shoots and roots Dermal tissue: covering for the plant body Ground tissue: support, photosynthesis, and storage Vascular tissue: conduction of water, food, and dissolved minerals; strengthens and supports the plant

Meristematic 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

Region of cell differentiation /maturation

Apical meristem



Region of cell elongation

In shoot tips and root tips Allium cepa root tip

Region of cell division

Apical meristem Root cap

Dermal Tissues


Single layer of cells called the epidermis in herbaceous plants







Epidermis

Guard cells Trichomes Root hairs

Functions





Absorption Secretion of cuticle Protection Control of gas exchange

Cuticle

The Ground Tissue System

Parenchyma 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

Collenchyma










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

Sclerenchyma







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 Tissue System

Complex Vascular Tissues


Xylem





Phloem






Conducts water and dissolved minerals from the roots

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