Plant Cells Plant Cells and and

TissuesTissues

I. General InformationI. General Information

A. Three main plant cell typesA. Three main plant cell types1. Parenchyma1. Parenchyma2. Collenchyma2. Collenchyma3. 3. SclerenchymaSclerenchyma

1. Parenchyma1. Parenchymaa.a. Can differentiate into all Can differentiate into all

cell typescell typesb.b. Living cell, can still divideLiving cell, can still dividec.c. F(x)sF(x)s = =

Plant growthPlant growthFood production (photosynthesis)Food production (photosynthesis)Food storage (e.g. potatoes)Food storage (e.g. potatoes)Wound healing & regenerationWound healing & regeneration

2. Collenchyma2. Collenchymaa. Living cellsa. Living cellsb. Have thicker walls than b. Have thicker walls than

parenchymaparenchymac. Can form long ropec. Can form long rope--like fiberslike fibers

(e.g. linen)(e.g. linen)d. Can stretch (occur in elongation zones)d. Can stretch (occur in elongation zones)e. e. F(xF(x) = strength, support, elongation) = strength, support, elongation

3. 3. SclerenchymaSclerenchymaa.a. Usually dead while functioningUsually dead while functioningb.b. Thick secondary wall, no stretchThick secondary wall, no stretchc.c. F(xF(x) = strength, support) = strength, supportd.d. 2 types: 2 types:

i. fibersi. fibersii. ii. SclereidsSclereids

(seed coats, (seed coats, nut shells nut shells & fruit)& fruit)

?s 1?s 1--55

I. General InformationI. General Information

B. Three main types of plant tissueB. Three main types of plant tissue1. 1. Ground tissueGround tissue

2. 2. Dermal TissueDermal Tissue

3. 3. Vascular TissueVascular Tissue

C. C. Ground tissueGround tissue1. Surrounded by 1. Surrounded by

dermal tissuedermal tissue2. All tissue that is 2. All tissue that is

NOT dermal NOT dermal tissue or vascular tissue or vascular tissuetissue

C. C. Ground tissueGround tissue3. Contains all three types of cells3. Contains all three types of cells

(mostly parenchyma)(mostly parenchyma)

4. Make up most of non4. Make up most of non--woodywoodyroots, stems & leavesroots, stems & leaves

C. C. Ground tissueGround tissue

5. 5. Many Many f(x)sf(x)sPhotosynthesisPhotosynthesisFood storageFood storageSupportSupport

C. C. Ground tissueGround tissue

D. D. Dermal TissueDermal Tissue

1. General1. Generala.a. Forms the Forms the ““skinskin””

(outside covering) of a plant(outside covering) of a plantb. Covers roots, stems & leavesb. Covers roots, stems & leavesc. c. F(xF(x) depends on ) depends on

locationlocation

D. D. Dermal TissueDermal Tissue

d. Examples:d. Examples:EpidermisEpidermisCuticleCuticleRoot HairsRoot HairsStomataStomataCorkCork

D. D. Dermal TissueDermal Tissue

2. 2. EpidermisEpidermisa. Parenchymaa. Parenchymab. Usually b. Usually ONE ONE

cell thickcell thickc. Outer protective c. Outer protective

covering of youngcovering of young& mature woody & mature woody

plantsplants

D. D. Dermal TissueDermal Tissue3. 3. CuticleCuticle

a.a. Waxy layer Waxy layer secreted secreted

by by epidermisepidermis

b. b. F(xF(x) = ) = prevent prevent dehydrationdehydration

D. D. Dermal TissueDermal Tissue

4. 4. Root HairsRoot Hairs

a.a. Modification Modification of epidermisof epidermis

b. b. F(xF(x) =) =AbsorptionAbsorptionof water from soilof water from soil

D. D. Dermal TissueDermal Tissue

5. 5. StomataStomataa. Location = stems a. Location = stems

&&leavesleaves

b. b. F(xF(x) = ) = osmoregulationosmoregulation & & regulation of regulation of gas exchangegas exchange

D. D. Dermal TissueDermal Tissue

c. Composition: c. Composition: two guard cells two guard cells stoma (opening)stoma (opening)

Guard cells

stoma

D. D. Dermal TissueDermal Tissue

6. 6. Cork (bark)Cork (bark) ((Dead cells)Dead cells)a.a. F(xF(x) = ) =

i. Replace i. Replace epidermis epidermis in woody in woody stems & stems & rootsroots

ii. Protectii. Protectplantplant

cork

E. E. Vascular TissueVascular Tissue

1.1. F(x)sF(x)s

a. a. TransportsTransports water & nutrients water & nutrients

b. b. SupportsSupports the plantthe plant

E. E. Vascular TissueVascular Tissue

2. Two kinds of vascular tissue2. Two kinds of vascular tissue

a. a. Xylem Xylem

b. b. PhloemPhloem

E. E. Vascular TissueVascular Tissue

3. 3. XylemXylema.a.F(xF(x) = ) =

Conducts Conducts Water & Nutrients Water & Nutrients UPUP

from rootsfrom roots(X elevator only goes up)(X elevator only goes up)

3. 3. XylemXylem

b. Two kinds of conducting cellsb. Two kinds of conducting cells

i. i. TracheidsTracheidslong, thicklong, thick--walled walled

scelerenchymascelerenchymaThin separations Thin separations between thembetween them

i. i. TracheidsTracheids

Water Water moves moves betweenbetween them them through through PITSPITS(thin porous (thin porous areas of areas of cell wall)cell wall)

3. 3. XylemXylem

ii. ii. Vessel Elements (members)Short, wide sclerenchymaNo end wallsNo separations btwn. them

(arranged end to end)Not found in Gymnosperms

Tracheids vs Vessel Elements

4. 4. PhloemPhloema.a. F(xF(x) = ) =

conducts the conducts the PProducts of roducts of PPhotosynthesis hotosynthesis

in every directionin every direction((PP elevator moves in every direction)elevator moves in every direction)

4. 4. PhloemPhloemb. Two kinds of conducting cellsb. Two kinds of conducting cells

1. 1. Sieve Tube MemberSieve Tube Membera. a. F(xF(x) = Conduct sap) = Conduct sapb. Stacked to form long b. Stacked to form long

SieveTubesSieveTubes

4. 4. PhloemPhloem2. 2. Companion CellsCompanion Cells

a. Parenchymaa. Parenchymab. b. F(xF(x) = Control movement of ) = Control movement of

sap through sieve tubessap through sieve tubes