Plant Form & FunctionPlant Anatomy

AP BiologyBloomington High School

Plant Tissues

• Ground tissues• Parenchyma

– Thin walls– Storage– Photosynthesis– Secretion

Plant Tissues

• Ground tissues• Collenchyma

– Thick, flexible walls

– Support

Plant Tissues

• Ground tissues• Sclerenchyma

– Thick walls– Support

Plant Tissues

• Dermal Tissue• Epidermis

– Cover surface of plant– Guard cells-

Plant Tissues

• Vascular Tissue• Xylem

– Transports water & minerals

– Tracheids– Vessel elements

Plant Tissues

• Vascular Tissue• Phloem

– Transports food– Sieve-tube members– Companion cells

Primary vs. Secondary Growth

• Primary Growth• Growth in length• Apical meristems• Tips of roots & shoots

Primary vs. Secondary Growth

• Secondary Growth• Growth in width• Lateral meristems• Vascular cambium• Cork cambium

Root Tip

• Root cap• Protects apical

meristem

Root Tip

• Zone of cell division• Cells divide• Apical meristem

Root Tip

• Zone of elongation• Cells absorb water &

elongate

Root Tip

• Zone of maturation• Cells mature• Perform specific

functions• Cells differentiate• Root hairs

Herbaceous Dicot Stem

• Epidermis• Outer layer

of cells• Provides

protection

Herbaceous Dicot Stem

• Cortex• Ground

tissue• May contain

chloroplasts

Herbaceous Dicot Stem

• Pith• Storage• Provides

support through turgor pressure

Herbaceous Dicot Stem

• Vascular Bundle

• Xylem & phloem

• Occur in rings

Herbaceous Dicot Stem

• Vascular Bundle• Bundle cap• Cells

– Dead– Fibrous– Thick walled

• Sclerenchyma cells

• Provide support

Herbaceous Dicot Stem

• Vascular Bundle• Phloem• Transports food• Sieve-tube members

– Long– Living cells

• Companion cells– Small– Parenchyma cells

Herbaceous Dicot Stem

• Vascular Bundle• Xylem• Transports water• Tracheids

– Dead– Thick walled

• Vessel elements– Large diameter– Dead

Herbaceous Dicot Stem

• Vascular Bundle• Vascular cambium• Between xylem &

phloem• Cells divide to form

xylem & phloem

Woody Stem

• Pith

Woody Stem

• Xylem• Wood

Woody Stem

• Xylem• Wood• Summer wood

– Small cells– Less water

• Spring wood– Large cells– More water

Woody Stem

• Xylem• Annual rings• 1st year’s growth• 2nd year’s growth• 3rd year’s growth

Woody Stem

• Bark• Phloem• Cortex

Woody Stem

• Vascular cambium

• Between xylem & phloem

• Produces newxylem & phloem cells

• Secondary growth

Dicot Root Cross Section

• Epidermis• Absorbs water• Root hairs

increase surface area for water absorption

• In older roots provides protection

Dicot Root Cross Section

• Cortex• Bulk of root• Stores starch

Dicot Root Cross Section

• Vascular cylinder• Stele• Xylem & phloem• Outlined by

endodermis

Dicot Root Cross Section

• Vascular cylinder• Xylem• Large cells• Dead• Transport water

& minerals

Dicot Root Cross Section

• Vascular cylinder• Phloem• Small cells• Transport food

Dicot Root Cross Section

• Vascular cylinder

• Endodermis• Casparian strip

– Waxy– Forms barrier

• All water must pass through endodermis before entering stele

Leaf

• Upper epidermis• Provides

protection• Cuticle

– Waxy– Decreases

water loss

Leaf

• Lower epidermis• Contains stomata

– Holes

– Allow CO2 in &O2 & H2O out

– Surrounded byguard cells

Leaf

• Palisade mesophyll• Parenchyma

cells• Tightly packed• Photosynthesis

Leaf

• Spongy mesophyll• Parenchyma

cells• Loosely

arranged• Photosynthesis• Air spaces

Leaf

• Vascular bundle• Veins• Xylem (red) &

phloem (green)• Bundle sheath

cells surround bundles