Ground Tissue

ground tissue

variety of functions 
bulk of plants body 

ground tissue found between

epidermis/skin and vascular/transport tissue 

types of ground tissue

1. parenchyma + chlorenchyma

2. collenchyma

3. sclerenchyma

why does parenchyma have air spaces

gaseous exchange 

parenchyma shape

roundish with air spaces 

parenchyma characteristics

• thin walled cells

• intercellular spaces between cells

• large central vacuole

• specialised parenchyma cells, chlorenchyma contain chloroplasts and are found in leaves 
  (tils)

parenchyma tissue

forms most stems and root tissue as well as soft fruit like tomatoes and grapes
most common
storage of nutrients 

most common ground tissue

parenchyma 

parenchyma responsible for

storage of nutrients 

parenchyma - thin walled cells - function

allows for close packing and rapid diffusion between cells 

parenchyma - intercellular spaces between cells - function

gasesous exchange

parenchyma - large central vacuole - function

allows cells to store + regulate ions (salts), waste, water, + stores starch in leucoplasts + provides support (when turgid) 

chlorenchyma functions

• photosynthesis
  - storage of starch in leucoplasts 

parenchyma function in a leaf

photosynthesis and gaseous exchange

parenchyma function in roots

carb storage 

chlorenchyma

specialised type of parenchyma tissue that photosynthesises, contains chloroplasts 

leaf layers

cuticle with trichomes
palisade mesophyll layer
spongy mesophyll layer
guard cells + stoma + cuticle

palisade layer

closely packed column shaped cells with many chloroplasts 

spongy layer

loosely packed isodiametric cells with fewer chloroplasts 

collenchyma

simple, permanent tissue found in shoots and leaves of plants

collenchyma: cells are spherical oval or polygonal in shape with no intercellular spaces - function

close packing for structural support 

collenchyma corners of cell wall thickened with cellulose and pectin deposits - function

provides mechanical strength
strong strands in celery stalks 

collenchyma cells thin walled on most sides - function

provides flexibility, allowing plant to bend in wind 

sclerenchyma tissue

supporting tissue - makes hard and stiff

2 types sclerenchyma cells

1. fibres

2. sclereids

sclerenchyma fibres

long and narrow and have thick lignified cell walls - provide mechanical strength to plant and allow for conduction  of water 

sclerenchyma sclereids

cells with thickened highly lignified walls with pits that support soft tissues of pears and guavas and found in shells of some nuts 

sclerenchyma cells are dead and have lignified secondary cell walls - function

provides mechanical strength and structural support
lignin provides 'wire-like' strength to prevent tearing easily 

sclerenchyma sclereid cells have strong walls which fill nearly entire volume of cell - function

provide hardness of fruits like pears - structures used to  protect other cells 

pectin

acidic carb 

stone cells

sclereids 

parenchyma cells

• thin walled

• large vacuoles

• rounded and elongated

• can contain chlorophyll (chlorenchyma)

• usually makes up pith of plant stems 

parenchyma functions

1. photosynthesis (chlorenchyma) 

2. storage - starch, oils and water

3. secretions - hormones, enzymes, nectars

4. meristematic function - can differentiate

5. filling tissue - thin walls and large vacuoles make turgid cells 
   
   pssmf

parenchyma cells function in leaves

photosynthesis and gas exchange 

parenchyma tissue forms

most stems and root tissue, as well as soft fruit like tomatoes and grapes 

chlorenchyma

specialised type of parenchyma tissue that photosynthesises, contains chloroplasts 

palisade layer

closely packed, column shaped cells, many chloroplasts 

spongy layer

loosely packed, isodiametric cells, fewer chloroplasts 

2 regions of chlorenchyma tissue

palisade and spongy 

collenchyma tissue found in

shoots and leaves of plants 

corners of collenchyma thickened with

cellulose 

cellulose thickened corners in collenchyma

strength, in growing shoots and leaves&nbsp;<br>

collenchyma characteristics

• spherical oval or polygonal cell shape with no intercellular spaces

• corners of cell wall are thickened with cellulose and pectin deposits

• cells are thin walled on most sides 

collenchyma: cells are spherical oval or polygonal in shape with no intercellular spaces - function

close packing for structural support&nbsp;

collenchyma corners of cell wall thickened with cellulose and pectin deposits - function

provides mechanical strength<br>strong strands in celery stalks&nbsp;

collenchyma cells thin walled on most sides - function

provides flexibility, allowing plant to bend in wind&nbsp;

sclerenchyma tissue

supporting tissue - makes hard and stiff

sclerenchyma fibres

long and narrow and have thick lignified cell walls - provide mechanical strength to plant and allow for conduction&nbsp; of water&nbsp;

sclerenchyma sclereids

cells with thickened highly lignified walls with pits that support soft tissues of pears and guavas and found in shells of some nuts&nbsp;

sclerenchyma cells are dead and have lignified secondary cell walls - function

provides mechanical strength and structural support<br>lignin provides 'wire-like' strength to prevent tearing easily&nbsp;

sclerenchyma sclereid cells have strong walls which fill nearly entire volume of cell - function

provide hardness of fruits like pears - structures used to&nbsp; protect other cells&nbsp;

parenchyma identifiers

blobs,<br>&nbsp;large round cells with thin walls<br>spaces between cells&nbsp;

collenchyma identifiers

rounded cells<br>irregular thickening in primary walls&nbsp;

sclerenchyma identifiers

rounded cells with pointed end to primary walls<br>thick secondary wall&nbsp;

parenchyma living or dead

living

parenchyma cell walls

thin cellulose

parenchyma flexibility

soft

parenchyma main function

storage, photosynthesis, gas exchange&nbsp;

parenchyma air spaces

present

parenchyma found in

cortex, pith, leaves&nbsp;

collenchyma living or dead

living&nbsp;

collenchyma cell walls

unevenly thickened cellulose and pectin

collenchyma flexibility

flexible

collenchyma main function

flexible support&nbsp;

collenchyma air spaces

few or none&nbsp;

collenchyma found in

young stems, petioles, leaf veins&nbsp;

sclerenchyma living or dead

dead at maturity&nbsp;

sclerenchyma cell walls

very thick, lignified&nbsp;

sclerenchyma flexibility

rigid

sclerenchyma main function

strong mechanical support&nbsp;

sclerenchyma air spaces

none

sclerenchyma found in

seed coats, fibres, vascular bundles&nbsp;