shoots ...
Plant Cells and Plant Tissues II Slide One – epidermis (root / shoots / leaves) Slide Two – variation on a theme Slide Three –epidermal hairs (root) •
Nutrient and water uptake
•
Some cells instead of being platelet cells, become single cell thick root hairs
•
The zone where the root takes up nutrients are limited to root hairs
Slide Four – epidermal glands •
Glands are the heads filled with liquid on a stalk
•
Glands are the organ that produces THC (in hemp – cannabis sativa)
Slide Five – stinging hairs •
act as protection against herbivores o
Stinging nettle made of silica nettles and injects chemicals inside skin of animal attacking it
Slide Six – conical epidermis •
Act as a source of attraction
•
Conical epidermis creates a velvety sheen
Slide Seven – epidermal platelets •
Protection against the sun (too much light)
•
Silverberry grows in the open and suffers water shortage o
it grows its epidermis into large platelets that protect the epidermis underneath from water loss
Slide Eight – h2o repellent epidermis •
lotus needs a water repellent surface to ensure effect gas exchange
•
growing tiny cone shaped structures that cause water to aggregate and fall off the lotus
Slide Nine – epidermal sensing hairs
•
venus fly trap
Slide Ten – epidermis of the pitcher plant •
pitcher plant lacks in nitrogen
•
modified leaf filled with water mixed with digestive juices o
any insects that fall in are digested for nitrogen content
o
trichomes on the outside on the leaf to facilitate ladder-like function for insects
o
inside of leaf is smooth and insects slide into the digestive juices
Slide Eleven – boring Slide Twelve – periderm (protection / exchange) Slide Thirteen – perennial plants •
growing two or more years as opposed to annual plants growing one year
•
wear and tear of epidermis
•
growth of stem -> ripping apart of epidermis
•
periderm is used for the sealing and maintenance of epidermis
Slide Fourteen – woof •
periderm = bark
•
two cell types making up the periderm is o
the cork cambium (source of new periderm)
o
secondary meristem
cork cells (protection / actual bark)
dead at maturity / walls of lignin (anti-microbial) / and suberin (wax-like / against dessication)
Slide Fifteen – periderm formation •
cork cambium on the inside of the epidermis slowly forms cork cells
•
epidermis finally rips apart, but the cell is all good thanks to cork cells
Slide Sixteen – xylem •
transport / support / storage
Slide Seventeen – xylem •
tracheids (transport / support) o
•
dead at maturity
vessels (transport / support) o
dead at maturity
•
parenchyma (storage)
•
fibers (support)
Slide Eighteen – tracheids vs vessel members •
tracheids strongly tapered cells have tiny pores where water runs through (pith)
•
vessel members are evolutionarily more sophisticated o
water runs not only through piths, but also perforations
o
water can not only run vertically, but also horizontally
Slide Nineteen – tracheids •
thick lignified cell walls
•
h2o flows through adjacent piths from cell to cell
Slide Twenty – vessels •
thick lignified cell walls (variably enforced)
•
h2o flows through openings (perforations) and piths from cell to cell
Slide Twenty-One – xylem cross section •
tracheids in conifers alone are relatively weaker alone than tracheids / vessel members / fibers together in angiosperms
•
distinguished by softwood (conifers) and hardwood (angiosperms)
Slide Twenty-Two – xylem support
•
tracheids / vessels / fibers are more or less lignified resulting in hard and sturdy structures
Slide Twenty-Three – phloem (transport) Slide Twenty-Four – phloem •
sieve tube members (transport) o
•
continuous system transporting dissolved food material (primarily sugars) from leaves to rest of plants
companion cells (support) o
‘brain’ of the sieve tube members
Slide Twenty-Five – phloem •
Living cells
•
Sugar flows through sieve tube members divided by sieve plates
•
Companion cells: control both themselves and sieve tube members o
Sieve tube members lack nucleus and so are controlled by companion cells
Slide Twenty-Six – vascular system xylem + phloem Slide Twenty-Seven – vascular tissue (non woody plants) •
Vascular bundle is made up of phloem and xylem
•
Enforcing the vascular bundle is a collenchyma cap above it
Slide Twenty-Eight – vascular tissue (trees) •
Most of a tree is made up of xylem
•
Outside layers are comprised of the phloem and periderm (bark)
Slide Twenty-Nine – ground tissue (support / storage) •
Essentially what is not (xylem / phloem / epidermis / periderm) is ground tissue o
Tissues other than dermal and vascular tissue
Slide Thirty – ground tissue (non-woody plants)
•
Majority of ground tissue is made up of parenchyma > collenchymas > sclerenchyma
•
Photosynthesis (when it is close to the surface of plant) / store nutrients / fill space
Slide Thirty-One – characteristics of plant tissues •
Dermal tissue o
•
Flat living parenchyma in non-woody plants
Flat dead parenchyma (cork) in woody plants
o
Function in roots: water and nutrient absorption / protection
o
Function in stems: gas exchange / protection
o
Function in leaves: gas exchange / protection
Vascular tissue o
o •
Epidermis / Periderm
Xylem / Phloem
Dead xylem cells (water / minerals)
Living phloem cells (sugar / photosynthetic products)
Interspersed parenchyma and sclerenchyma
Function in roots / stems / leaves: transport / support
Ground tissue o
Mostly Parenchyma
Usually with some collenchymas and fewer sclerchyma
o
Function in roots / stems: support / storage
o
Function in leaves: photosynthesis
Nutrient and water uptake
•
Some cells instead of being platelet cells, become single cell thick root hairs
•
The zone where the root takes up nutrients are limited to root hairs
Slide Four – epidermal glands •
Glands are the heads filled with liquid on a stalk
•
Glands are the organ that produces THC (in hemp – cannabis sativa)
Slide Five – stinging hairs •
act as protection against herbivores o
Stinging nettle made of silica nettles and injects chemicals inside skin of animal attacking it
Slide Six – conical epidermis •
Act as a source of attraction
•
Conical epidermis creates a velvety sheen
Slide Seven – epidermal platelets •
Protection against the sun (too much light)
•
Silverberry grows in the open and suffers water shortage o
it grows its epidermis into large platelets that protect the epidermis underneath from water loss
Slide Eight – h2o repellent epidermis •
lotus needs a water repellent surface to ensure effect gas exchange
•
growing tiny cone shaped structures that cause water to aggregate and fall off the lotus
Slide Nine – epidermal sensing hairs
•
venus fly trap
Slide Ten – epidermis of the pitcher plant •
pitcher plant lacks in nitrogen
•
modified leaf filled with water mixed with digestive juices o
any insects that fall in are digested for nitrogen content
o
trichomes on the outside on the leaf to facilitate ladder-like function for insects
o
inside of leaf is smooth and insects slide into the digestive juices
Slide Eleven – boring Slide Twelve – periderm (protection / exchange) Slide Thirteen – perennial plants •
growing two or more years as opposed to annual plants growing one year
•
wear and tear of epidermis
•
growth of stem -> ripping apart of epidermis
•
periderm is used for the sealing and maintenance of epidermis
Slide Fourteen – woof •
periderm = bark
•
two cell types making up the periderm is o
the cork cambium (source of new periderm)
o
secondary meristem
cork cells (protection / actual bark)
dead at maturity / walls of lignin (anti-microbial) / and suberin (wax-like / against dessication)
Slide Fifteen – periderm formation •
cork cambium on the inside of the epidermis slowly forms cork cells
•
epidermis finally rips apart, but the cell is all good thanks to cork cells
Slide Sixteen – xylem •
transport / support / storage
Slide Seventeen – xylem •
tracheids (transport / support) o
•
dead at maturity
vessels (transport / support) o
dead at maturity
•
parenchyma (storage)
•
fibers (support)
Slide Eighteen – tracheids vs vessel members •
tracheids strongly tapered cells have tiny pores where water runs through (pith)
•
vessel members are evolutionarily more sophisticated o
water runs not only through piths, but also perforations
o
water can not only run vertically, but also horizontally
Slide Nineteen – tracheids •
thick lignified cell walls
•
h2o flows through adjacent piths from cell to cell
Slide Twenty – vessels •
thick lignified cell walls (variably enforced)
•
h2o flows through openings (perforations) and piths from cell to cell
Slide Twenty-One – xylem cross section •
tracheids in conifers alone are relatively weaker alone than tracheids / vessel members / fibers together in angiosperms
•
distinguished by softwood (conifers) and hardwood (angiosperms)
Slide Twenty-Two – xylem support
•
tracheids / vessels / fibers are more or less lignified resulting in hard and sturdy structures
Slide Twenty-Three – phloem (transport) Slide Twenty-Four – phloem •
sieve tube members (transport) o
•
continuous system transporting dissolved food material (primarily sugars) from leaves to rest of plants
companion cells (support) o
‘brain’ of the sieve tube members
Slide Twenty-Five – phloem •
Living cells
•
Sugar flows through sieve tube members divided by sieve plates
•
Companion cells: control both themselves and sieve tube members o
Sieve tube members lack nucleus and so are controlled by companion cells
Slide Twenty-Six – vascular system xylem + phloem Slide Twenty-Seven – vascular tissue (non woody plants) •
Vascular bundle is made up of phloem and xylem
•
Enforcing the vascular bundle is a collenchyma cap above it
Slide Twenty-Eight – vascular tissue (trees) •
Most of a tree is made up of xylem
•
Outside layers are comprised of the phloem and periderm (bark)
Slide Twenty-Nine – ground tissue (support / storage) •
Essentially what is not (xylem / phloem / epidermis / periderm) is ground tissue o
Tissues other than dermal and vascular tissue
Slide Thirty – ground tissue (non-woody plants)
•
Majority of ground tissue is made up of parenchyma > collenchymas > sclerenchyma
•
Photosynthesis (when it is close to the surface of plant) / store nutrients / fill space
Slide Thirty-One – characteristics of plant tissues •
Dermal tissue o
•
Flat living parenchyma in non-woody plants
Flat dead parenchyma (cork) in woody plants
o
Function in roots: water and nutrient absorption / protection
o
Function in stems: gas exchange / protection
o
Function in leaves: gas exchange / protection
Vascular tissue o
o •
Epidermis / Periderm
Xylem / Phloem
Dead xylem cells (water / minerals)
Living phloem cells (sugar / photosynthetic products)
Interspersed parenchyma and sclerenchyma
Function in roots / stems / leaves: transport / support
Ground tissue o
Mostly Parenchyma
Usually with some collenchymas and fewer sclerchyma
o
Function in roots / stems: support / storage
o
Function in leaves: photosynthesis
