TissueTissuean integrated group of cells an integrated group of cells

with a common structure with a common structure and functionand function

Plant tissuesPlant tissues1.1. Meristematic tissueMeristematic tissue: rapid cell : rapid cell

division, lengthening of shoots and division, lengthening of shoots and rootsroots

2.2. Dermal tissueDermal tissue: covering for the : covering for the plant bodyplant body

3.3. Ground tissueGround tissue: support, : support, photosynthesis, and storage photosynthesis, and storage

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

Meristematic TissueMeristematic Tissue• cells that cells that do not do not

differentiatedifferentiate• cells cells retain the ability to retain the ability to

dividedivide• Types:Types:

1.1. ApicalApical – – primary growthprimary growth at root and shoot tipsat root and shoot tips

2.2. LateralLateral – – secondary secondary growthgrowth in trees and in trees and shrubs shrubs

3.3. IntercalaryIntercalary – – secondary secondary growthgrowth in monocot in monocot stemsstems

Apical meristemApical meristem

• In shoot tips and In shoot tips and root tipsroot tips

• Allium cepaAllium cepa root tip root tip

Root cap

Apical meristemApical meristem

Region of cell Region of cell differentiationdifferentiation/maturation/maturation

Region of cell Region of cell elongationelongation

Region of cell Region of cell divisiondivision

Dermal TissueDermal Tissue• Single layer of cells called Single layer of cells called

the the epidermisepidermis in in herbaceous plantsherbaceous plants– guard cellsguard cells– trichomestrichomes– root hairsroot hairs

• FunctionsFunctions– absorptionabsorption– secretion of cuticlesecretion of cuticle– protectionprotection– control of gas exchangecontrol of gas exchange

Epidermis

Cuticle

Ground TissueGround TissuePARENCHYMA COLLENCHYMA SCLERENCHYMA

Characteristics • spherical• thin-walled• living, metabolizing tissue

• elongated cells with unevenly thickened cell walls• alive at maturity

• with primary and secondary cell walls• dead at functional maturity

Location • throughout the plant • beneath the epidermis in young stems and in leaf veins

• fibers in wood, bark, leaves, stems• sclereids in fruits and seeds

Functions • photosynthesis and respiration• storage• regeneration

• flexible support system

• structural support

Appearance

Vascular TissueVascular Tissue

• 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

FOUR TYPES OF ANIMAL FOUR TYPES OF ANIMAL TISSUESTISSUES

Epithelial TissueEpithelial Tissue(Covering)(Covering)• Tightly-joined closely-packed cells• One side of exposed to air or internal

fluid, other side attached to a basement membrane

• Covers outside of the body and lines internal organs and cavities

• Barrier against mechanical injury, invasive microorganisms, and fluid loss

• Provides surface for absorption, excretion and transport of molecules

Types of Types of Epithelial Epithelial TissueTissueCell shape

1. Squamous2. Cuboidal3. Columnar

Number of cell layers1. Simple2. Pseudostratified3. Stratified

RELATE STRUCTURE TO FUNCTION!

Binding and support of other tissues Large amount of extracellular matrix with

fewer cells ECM - network of fibers in liquid, jelly-like or

solid matrix

Muscle TissueMuscle Tissue(Movement)(Movement)

• Composed of long cells called muscle fibers

• Contraction movement

Nervous tissueNervous tissue(Control)(Control)

Senses stimuli and transmits nerve impulses

Single cell body with long extensions (axons and dendrites)

Axon

Dendrite

Cell body