Form and Function in plants
and animals
Monday, March 21, 2022 10:04 AM
• Typical root and shoot systems acquire and transport resources
○ Plants use two basic systems to acquire resources for photosynthesis
§ Shoot system harvest light and carbon dioxide from atmosphere to produ
sugars
§ Root system anchors plant and takes in water and nutrients from soil
§ Together, these systems make up the plant body
• Plant tissue systems
○ Plant tissues grouped into tissue systems, based on their structural features and
location within plants:
§ Simple tissues consist of single cell type; complex tissues contain several t
of cells
○ Each tissue system is continuous throughout the plant
○ Three tissue systems are found in plants:
§ Dermal tissue system
□ Complex tissue (different cell types)
® Epidermal cells (skin)
◊ Secrete the cuticle (waxy layer that is hydrophobic)
® Stomata
◊ Regulate gas exchange and water loss (guard cells: chan
shape to open and close the stoma)
® Trichomes:
◊ Hairlike appendages made up of specialized epidermal c
Reflect sunlight, reduce water loss, protect from herbivo
trap and digest insects (1 or multiple cells)
® Root hairs:
◊ Protection and absorption of water and nutrients
§ Ground tissue system
□ Most photosynthesis and carbohydrate storage takes place in the
ground tissue system
□ 3 different tissue (and cell) types:
® Parenchyma
, ®
◊ Have thin flexible primary walls
◊ Lack secondary walls
◊ Most abundant and versatile plant cells
◊ General type of cell with thin primary cell wall. Found in
leaves, centers of stems and roots, and fruits
◊ Parenchyma cells can divide and mature into complete
plants (Principle of totipotency)
® Collenchyma
◊ Unevenly thickened primary wall, longer and thinner th
parenchyma
◊ Provide flexible structural support to actively growing p
of the plant
◊ Found just under the epidermis of stems, especially out
vascular bundles
® Sclerenchyma
◊ Have thin primary cell wall and thick, rigid secondary ce
wall, strengthened with lignin as well as cellulose
◊ Sclerenchyma is a complex tissue with two types of
cells:>>>
◊ Sclerenchyma cells are dead at maturity and function to
support stems and other structures after growth has ce
§ Vascular tissue system
□ Made up of two complex tissues:
® Xylem:
} (parenchyma)
} Tracheids
} Vessel elements (in angiosperms and gnetophyta)
◊ Xylem conducts water and dissolved minerals from the
system to the shoot system
◊ The two types of water conducting cells, tracheids and
vessel elements, are dead at maturity
◊ Tracheids are found in the xylem of all vascular plants, w
pits through which water moves
◊ In angiosperms, xylem also contains vessel elements wit
perforations for water
◊ Vessel elements align end to end to form long micropip
called vessels
® Phloem:
and animals
Monday, March 21, 2022 10:04 AM
• Typical root and shoot systems acquire and transport resources
○ Plants use two basic systems to acquire resources for photosynthesis
§ Shoot system harvest light and carbon dioxide from atmosphere to produ
sugars
§ Root system anchors plant and takes in water and nutrients from soil
§ Together, these systems make up the plant body
• Plant tissue systems
○ Plant tissues grouped into tissue systems, based on their structural features and
location within plants:
§ Simple tissues consist of single cell type; complex tissues contain several t
of cells
○ Each tissue system is continuous throughout the plant
○ Three tissue systems are found in plants:
§ Dermal tissue system
□ Complex tissue (different cell types)
® Epidermal cells (skin)
◊ Secrete the cuticle (waxy layer that is hydrophobic)
® Stomata
◊ Regulate gas exchange and water loss (guard cells: chan
shape to open and close the stoma)
® Trichomes:
◊ Hairlike appendages made up of specialized epidermal c
Reflect sunlight, reduce water loss, protect from herbivo
trap and digest insects (1 or multiple cells)
® Root hairs:
◊ Protection and absorption of water and nutrients
§ Ground tissue system
□ Most photosynthesis and carbohydrate storage takes place in the
ground tissue system
□ 3 different tissue (and cell) types:
® Parenchyma
, ®
◊ Have thin flexible primary walls
◊ Lack secondary walls
◊ Most abundant and versatile plant cells
◊ General type of cell with thin primary cell wall. Found in
leaves, centers of stems and roots, and fruits
◊ Parenchyma cells can divide and mature into complete
plants (Principle of totipotency)
® Collenchyma
◊ Unevenly thickened primary wall, longer and thinner th
parenchyma
◊ Provide flexible structural support to actively growing p
of the plant
◊ Found just under the epidermis of stems, especially out
vascular bundles
® Sclerenchyma
◊ Have thin primary cell wall and thick, rigid secondary ce
wall, strengthened with lignin as well as cellulose
◊ Sclerenchyma is a complex tissue with two types of
cells:>>>
◊ Sclerenchyma cells are dead at maturity and function to
support stems and other structures after growth has ce
§ Vascular tissue system
□ Made up of two complex tissues:
® Xylem:
} (parenchyma)
} Tracheids
} Vessel elements (in angiosperms and gnetophyta)
◊ Xylem conducts water and dissolved minerals from the
system to the shoot system
◊ The two types of water conducting cells, tracheids and
vessel elements, are dead at maturity
◊ Tracheids are found in the xylem of all vascular plants, w
pits through which water moves
◊ In angiosperms, xylem also contains vessel elements wit
perforations for water
◊ Vessel elements align end to end to form long micropip
called vessels
® Phloem:
