The World of Plants

KINGDOM PLANTAE

What is a Plant: Plant CharacteristicsEUKARYOTIC – has a nucleus

MULTICELLULAR– more than one cell

AUTOTROPHIC – can make their own food, although some can be heterotrophic (i.e. Venus Fly Trap). SESSILE - remains stationary

CELL WALLS made of cellulose

WHAT DO PLANTS NEED TO SURVIVE? Sunlight – carry out photosynthesis

Water & Minerals – Needed to grow

Gas Exchange (CO2 – H2O) – Carry out cellular respiration

Movement of Water & Nutrients – to transport food and water from roots to leaves and leaves to roots.

Plants have Organs:

Leaves – gather sunlight to carry out photosynthesis

Stems – support the leaves and flowers Roots – anchor plants to the soil Flowers – carry out reproduction Vascular Tissue:

- Xylem: transport water & minerals from the roots.- Phloem: transport food (sugar/glucose) from the leaves to the rest of the plant

Cuticle

Upper epidermis

Mesophyll

Bundle sheathVascular tissue - Xylem - Phloem

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 ENVIRONMENTS

PINE NEEDLES (REDUCES WATER LOSS)

CACTUS NEEDLES TO PROTECT THEMSELVES FROM HERBIVORES

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Plants are divided into two groups based on whether they contain vascular tissue.

VasculaVascular r BundleBundless

Taxonomy of Plants

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Nonvascular PlantsNonvascular Plants Bryophytes do not

have vascular tissue.

They depend on water for reproduction so they live very close to the ground where water is in regular supply. MossMoss

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Tracheophytes: contain vascular tissue

They also contain seeds.

Club MossClub Moss

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Seed-Producing Vascular Seed-Producing Vascular PlantsPlants Includes two groups – Gymnosperms and

Angiosperms

Gymnosperms bears seeds on the surface of cones.

Angiosperms bear seeds within a protective layer (fruit).

GYMNOSPERMS(means “naked seed”)

most common group is the conifersExamples: fir, sprucepine.

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GymnospermsGymnosperms

Contains the oldest living plant – Bristle cone pine

Contains the tallest living plant – Sequoia or redwoodor redwood

CONIFERS: OLDEST SURVIVING TYPE OF SEED PLANTS. PRODUCE MALE AND FEMALE CONES.

FEMALE CONE IS WHERE POLLINATION BEGINS

MALE CONE PRODUCES POLLEN GRAINS

ANGIOSPERMS(“seeds encased in fruit)

flower bearing plants

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AngiospermsAngiosperms Flowering plants

Seeds are formed when an egg or ovule is fertilized by pollen in the ovary

Ovary is within a flower Flower contains the male

(stamen) and/or female (ovaries) parts of the plant

Fruits are frequently produced from these ripened ovaries (help disperse seeds)

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AngiospermsAngiosperms

Subdivided into two groups – Monocots and Dicots

Monocots have a single seed cotyledon

Dicots have two seed cotyledons

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MonocotsMonocots Parallel venation

in leaves

Flower parts in multiples of 3

Vascular tissue scattered in cross section of stem

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DicotsDicots Net venation in

leaves

Flower parts in multiples of 4 or 5

Vascular tissue in rings in cross section of stem

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

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

Petals Pistil:StigmaStyleOvary

Stamen: Anther Filament

Sepals

STEMS

1. Support leaves & flowers

2. Transport water and nutrientsthroughout the plant.

3. Some are adapted to store

food& remain dormant during inclement weather

STEMS: MAIN FUNCTIONS

2 TYPES OF ROOTS:1. Anchor plants2. Absorb water & minerals

TAP ROOTS ABLE TO REACH WATER FAR BELOW THE SURFACE

FIBROUS ROOTS PREVENT THE EROSION OF TOP SOIL FROM HEAVY RAINS.

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Why We Can’t do Without Why We Can’t do Without Plants!Plants!

Produce oxygen for the atmosphereProduce lumber for buildingProvide homes and food for many

organismsPrevent erosionUsed for food

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More Reasons We Can’t do More Reasons We Can’t do Without Plants!Without Plants!

Produce wood pulp for paper products

Source of many medicinesOrnamental and shade for yardsFibers such as cotton for fabricDyes