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