First Flowering Plants• Angiosperm: flowering plants– vascular– heterospory

• male vs. female gametophytes– flower

• specialized structure for sexual reproduction– seeds within fruit– pollen– life cycle dominated by

sporophyte stage• trees & bushes you are familiar

with are diploid• reduced (microscopic)

gametophyte

Angiosperm: flowering plants

PLANTS!

Basic Structure & Tissues (Ch. 29, Lecture 9)

General Plant Structure

Apical Meristems

Lateral meristem

Apical Meristems

•Apical meristem – localized region of cell division at the plant shoot & root tip

• Cells formed in the apical meristems differentiate into the plants various epidermal tissue cells.

Lateral Meristems

•Lateral meristems – add girth and protection to the stem of an older plant

• Vascular cambium – produces secondary vascular tissue

• Cork cambium – produces protective covering (periderm) that replaces epidermis

Land Plant Tissues

• Simple Tissues/Ground Tissue–Parenchyma – soft, primary growth tissue

in stems & leaves• Primary component of ground tissue)

–Collenchyma – support for soft tissues; ribs in leaf stalks– Sclerenchyma – fibrous protective tissue

(fortified with lignin)

Simple Tissues

Fibrous support structures

Sclereid cell fortified with

lignin

Land Plant Tissues

• Complex Tissues/Vascular Tissues–Xylem – transport of water & ions;

mechanical support–Phloem – transports sugars and solutes

Complex TissuesXylem “pipelines” (water transport)

Live Phloem sieve tubes for sugar & solute transport

Land Plant Tissues

• Dermal Tissues– Epidermis – unspecialized plant surface cells • Stomata – gaps in epidermis to allow material

passage• Cuticle – waxy surface coating to prevent water loss

– Periderm – protective outer covering, replaces epidermis• Forms bark in trees

Dermal Tissues

Photosynthesis is happening in the

parenchyma cells!

Epidermal cells secrete waxy cutin

to make cuticle

Monocots & Dicots Palms, lilies, bamboo etc…

Maple tree, peas, cacti etc…

Shoots & Leaves• Shoot – above ground plant parts– Bud – gives rise to leaves & flowers– Vascular bundles – organization of xylem & phloem– Cortex – outer stem layer, coats vascular bundles– Pith – center of stem

Shoots

Monocot vs. Dicot Shoots

• Monocot– Scattered vascular bundles throughout stem

• Dicot– Rings of vascular bundles around ground tissue

Pith

EpidermisEpidermis

Shoots & Leaves

• Leaf – metabolic factory for photosynthesis– Epidermis – coats leaf; openings called

stomata–Mesophyll – photosynthetic tissue made of

parenchyma tissue–Veins – leaf vascular bundles

Leaves

Roots

• Root Tissues– Stele~ the vascular bundle where both xylem and phloem develop– Pith~ central core of stele in monocot; parenchyma cells– Cortex~ region of the root between the stele and epidermis

(innermost layer: endodermis)• Primary Root – first root to emerge from seed• Lateral Root – outer layer/branches; may become

meristematic• Taproot System – primary “central” root & laterals

– Dandelions, carrots, oak trees, etc… • Fibrous Root System – multiple lateral roots

– Grasses

Primary Root Structure

Lateral root

Lateral Root Formation

Taproot vs. Fibrous Root