The World of Plants

KINGDOM PLANTAE

THE DOMINANT ORGANISMS ON LAND.

PLANTS PROBABLY EVOLVED FROM MULTICELLULAR AQUATIC GREEN ALGAE THAT COULD NOT SURVIVE ON LAND.

WHAT ARE PLANTS?

PLANT CHARACTERISTICS:EUKARYOTIC – has a nucleus

MULTICELLULAR– more than one cell

AUTOTROPHIC – can make own food * have chlorophyll * carry out photosynthesis SESSILE - remains stationary

CELL WALLS OF CELLULOSE

PLANT STRUCTUREHAVE TRUE TISSUE

1. Dermal-“Skin” for protection(thick bark, spongy cork or tight sheath on stems) -Produces cuticle

2. Vascular – for transport -Xylem carries water

- Phloem carries sugars 3. Ground – storage, structure &

photosynthesis

HAVE ORGANS: 1. LEAVES to gather sunlight

2. STEMS to support leaves

and flowers

3. ROOTS for anchoring

4. FLOWERS for reproduction and to make seeds.

Plant Structure (cont.)

THREE WAYS TO CLASSIFY PLANTS

1. Vascular (all trees, vines, flowers)

Non-vascular (moss)

2. Seeds (formed in a cone or fruit)

No Seeds (spores in mosses or ferns)

3. Flowers (angiosperms) No Flowers (gymnosperms such

as pines, firs, spruces, etc.)

MOSSES areseedless, non-vascular plants.

They were the first land plants.

FERNS: LARGEST GROUP OF SEEDLESS VASCULAR PLANTS

Fern Facts:* Live in moist habitat

* Need water for reproduction

* Have true leaves, stems & roots

* Vary in size and shape

* Grow on vines and float on the surface of water

SEEDS: 2 TYPES OF SEED-BEARING PLANTS

GYMNOSPERMS (means “naked seeds) cone-bearing trees such as firs, pines… produce seeds inside thin cones.

CONIFERS: OLDEST SURVIVING TYPE OF SEED PLANTS. PRODUCE MALE AND FEMALE CONES.FEMALE CONE IS WHERE POLLINATION BEGINS

MALE CONE PRODUCES POLLEN GRAINS

ANGIOSPERMS(means “seeds encased in fruit)

flower bearing plants

2 Major Groups of Flowering Plants

Monocots: Seeds that have only one cotyledon.(inc. bamboocorn, wheat)

Dicots: Seeds that have two cotyledons(inc. peas, tomatoes, roses, daisies, etc.)

Leaves

Cuticle

Upper epidermis

Mesophyll

Bundle sheath

Vascular tissue

Lower epidermis

Guardcells

chloroplaststoma

LEAF STRUCTURE

CUTICLE: waxy waterproof layer that coats the outer parts to help prevent evaporation of moisture.

MESOPHYLL: the middle part of the leaf where most of photosynthesis is carried out.STOMATA: pore-like openings that allow CO2 and O2 to diffuse in and out of the leaf.GUARD CELLS: specialized cells that control the opening and closing of the stomata by responding to changes in water pressure.

LEAF ADAPTATIONSCHANGES IN STRUCTURE OR FORM THAT ALLOW FOR BETTER SURVIVAL IN SPECIFIC ENVIRONMENTSPINE NEEDLES (REDUCES

WATER LOSS)

CACTUS NEEDLES TO PROTECT THEMSELVES FROM HERBIVORES

STEMS

1. Support leaves & flowers

2. Transport water and nutrients throughout the plant. 3. Some are adapted to store food

& remain dormant during inclement weather

STEMS: MAIN FUNCTIONS

STEM ADAPTATIONS:

TUBERS GROW UNDERGROUND AND STORE FOOD.

BULBS CAN REMAIN DORMANT FOR A LONG TIME YET STILL GROW INTO A PLANT

ROOTS: 2 TYPES

1. Anchor plants

2. Absorb water & minerals

TAP ROOTS - ABLE TO REACH WATER FAR BELOW THE SURFACE

FIBROUS ROOTS PREVENT THE EROSION (WASHING AWAY) OF TOP SOIL FROM HEAVY RAINS.

FLOWERSThe reproductive organ of a flowering plant

FUNCTION - produce male (sperm) and female (egg) gametes & provide a structure for fertilization.

Designed to attract specific pollinators.

PARTS OF A FLOWER

PetalsPistil:

StigmaStyleOvary

Stamen: Anther Filament

Sepals

Plant Adaptations: Brought about by Natural Selection to ensure survival of different circumstances.

1. Biomes2. Feeding Strategies3. Chemical Defenses

BIOMES:AQUATIC PLANTS ABLE TO TOLERATE MUD SATURATED WITH WATER AND LITTLE TO NO OXYGEN HAVE TISSUE WITH LARGE AIR-FILLED SPACES TO ALLOW THE DIFFUSION OF OXYGEN.

Ex.: LILY PADS

SALT-TOLERANT PLANTS – HAVE SPECIALIZED CELLS THAT PUMP SALT OUT OF THE TISSUE AND ONTO THE LEAF SURFACE TO BE WASHED OFF BY THE RAIN.

Ex.: MANGROVE TREES

DESERT PLANTS: MUST ENDURE HOT TEMPERATURES IN THE DAY, DRY AIR, AND INFREQUENT RAIN.EXTENSIVE ROOTS, REDUCED LEAVES AND THICK STEMS ARE THE MAIN ADAPTATIONS OF DESERT PLANTS.

CACTUS HAVE LEAVES THAT ARE REDUCED TO THIN, SHARP SPINES TO REDUCE WATER LOSS AND THICK GREEN STEMS TO STORE WATER AND CARRY OUT PHOTOSYNTHESIS

FEEDING STRATEGIES:

VENUS FLY TRAP

IF AN INSECT TRIGGERS THE HAIRS ON THE LEAF, THE LEAF FOLDS UP TRAPPING THE INSECT INSIDE.

PITCHER PLANTS DROWN THEIR PREY IN THEIR LEAVES THAT CONTAIN RAINWATER AND DIGESTIVE ENZYMES.

MISTLETOE IS A PARASITIC PLANT , EXTRACTING WATER AND NUTRIENTS FROM ITS HOST PLANT.

CHEMICAL STRATEGIES – PRODUCE A CHEMICAL COMPOUND THAT HAS A POWERFUL EFFECT ON PREDATORY INSECTS.

DIGITALIS PLANT:

POISONOUS TO MOST INSECTS OR ANIMALS WHEN EATEN.

TOBACCO PLANTS CONTAINS NICOTINE WHICH DISRUPTS THE NERVOUS SYSTEM OF PREDATORY INSECTS.

THE MILKWEED PLANT IS TOXIC TO MOST INSECTS WITH THE EXCEPTION OF THE MONARCH BUTTERFLY.

Main Role in Environment• Plants are the producers

• First link in the food chain• Provide habitats for animals

Things Plants Produce

Constructionmaterials

food

fuel

medicines

oxygen