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Plant Characteristics:
 Multicellular
 Eukaryotic
 Autotrophic
 Sessile means cannot move
 Have cellulose in their cell walls
chloroplast
Golgi
vacuole
Cell wall
body
nucleus
mitochondria
Cell membrane
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2 stages to photosynthesis
STAGE 1 THE LIGHT REACTION
CHLOROPLASTS CAPTURE
ENERGY FROM THE SUN
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STAGE 2 THE DARK REACTION
LIGHT ENERGY USED TO PRODUCE
SUGARS AND O2
FROM H20 AND CO2
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PLANT LIFE CYCLE
Sporophyte plant
= 2N
Spores are
1N
Zygote = 2N
Gametophyte
plant = 1N
ALTERNATION OF GENERATIONS
ALTERNATE PHASES (2N & 1N) IN PLANT LIFE CYCLE

FERTILIZATION= EGG + SPERM
(the joining together of the
egg and sperm
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
1N = Haploid = ½ the chromosomes

Gametophyte = 1N

2N = Diploid = full set of chromosomes

Sporophyte = 2N
ZYGOTE= SPERM + EGG (it’s the product of
fertilization) =2N (diploid) it’s a fertilized egg!!
 Plants evolved from the GREEN ALGAE
(PROTISTA)
 Contain chlorophyll a+b
 Fossil evidence (440,000,000 years ago)
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Adaptations which allowed plants to
grow on land:
 Cuticle – waxy covering to prevent water
loss
o Keeps plant from drying out
 Modified leaves (Shapes & Stomata)
Broad flat leaves better for
photosynthesis
Leaves placed for best light
absorption
Stomata for better gas exchange
**Opening in the underside of
the leaf
 Roots – take in water and anchor the plant
 Stem – support for growth and food storage
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
Vascular development – transport food and
water
*simple plants use only diffusion
height limited!!
Vascular system allows water and nutrients
to go to the whole plant
now can be TALL plants!!
 Seed development – protects gametes
Gametes
are the
sex cells
 Alternation of generations (Sporophyte &
Gametophyte)
 Sexual reproduction
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Two major groups
1.
NON VASCULAR PLANTS
No developed system for transporting H2O &
nutrients
Must get H2O DIRECTLY from their
surroundings
Plants are small, LOW TO THE
GROUND and must live in shady, DAMP
places
Hornwort
Liverwort
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2.
VASCULAR PLANTS
Have a transport system!!
Now can live on Dry Land!
Vascular tissue provides
 Support
 Strength
 Stability
Plants without seeds
NON VASCULAR PLANTS
Phylum Bryophyta
Low growing (short) plants
Live in moist (wet) areas =get water from surroundings
Water needed for reproduction
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EXAMPLES OF NON VASCULAR NO SEEDS:
Mosses:
very diverse group, found everywhere
 GAMETOPHYTE GENERATION SEEN
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Liverwort –named for the gametophyte
Hornwort-named for the sporophyte
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SEEDLESS Vascular Plants
Characteristics:
Have VASCULAR tissue
Reproduce using SPORES
Tall plants
Grows in moist surroundings
Examples:
Ferns:
cuticle upper surface
blade
Rhizome
Roots
Underground stem of a fern
SORI
GROUPS OF
SPORES
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CLUB MOSSES
HORSETAIL
_________________________________________
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2 Types:
 Xylem: transports water
 Phloem: transports food
(from photosynthesis)
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YAY!! Now H2O NOT needed for fertilization!!!
This is a
BIG
DEAL. Plants can now move away
from the edge of the water.
 POLLEN is now the sperm cell (male)
 SEEDS
o occur after fertilization
Egg + Pollen = Seed
 Definition: Seeds are structures that contain a young
plant inside a protective covering
STOPS THE
SEED FROM
DRYING OUT
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3 MAIN PARTS
EMBRYO
COTYLEDONS
SEED COAT
• Has all the
main parts of
the adult
plant
• can be stored
food
• seed leaf
• keeps
embryo from
drying out
• allows seed
to remain
inactive for
long periods
CORN
STEM
ROOT
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***Must have enough water! Seed absorbs H2O***
 Embryo begins to grow again and pushes out of
the seed
 Roots grow DOWNWARD
 Stems grow UPWARD
*** SEEDS CALLED SEEDLING ONCE THE
PLANT’S LEAVES ARE SEEN***
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NEEDED FOR
SUCCESS OF
PLANTS
(private life of plants “travelling” 10:05-22)
Animals
o Attachment
o Digestive tract (elephants, birds)
H2O
Wind
Ejection
ROOTS
Function: 1) Anchor plants
2) Absorb H2O & minerals for
Soil
3) Sometimes store food
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2 types of roots
Fibrous Roots
Tap Root
Dense tangle
of roots,
takes lots of
dirt with it
when pulled
out
Example:
Lawn grass
One LONG
main root
Smaller roots
branch off
Example:
Carrots &
Dandylions
Corn & Onions
Root Structure
Root cap: protects the root from injury
Dividing cells: area of new growth
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Root hairs: increase water absorption and
minerals absorption by increasing the surface
area
Root hair
Area of dividing cells =
MITOSIS
ROOT CAP
See page
267
Function:
Support the plant (so leaves can get the most
sun
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Carries substances between the leaves and
root
Two types of stems
Herbaceous Stems:
-soft stems
-example: pepper plants
Woody Stems:
-Hard, rigid stems
-Example: roses, trees
Annual Rings:
Each ring of system (a
band of light wood and a
band of dark wood)
represents one year’s
growth
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LEAVES
Cuticle
Upper leaf cells
Lower
leaf
cells
xylem
Stomata
phloem
VEIN
Upper leaf cells:
The most chloroplasts are located here
Tightly packed together
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Lower leaf cells:
Widely spaced cells allows CO2 to reach cells
for photosynthesis
Stomata:
“mouth” tiny openings that allow gases to enter
and exit the leaf
Stomata close to retain H2O
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GYMNOSPERMS
"Naked" seeds
oldest type of
seed plant
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ANGIOSPERMS
Flowering plants
seeds are
protected by
fruit
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Gymnosperms Naked seeds
 Cycadophyta (Cycads – produce male & female cones)
 Ginkgophyta (Ginkgo – seeds on female trees smell
really bad)
 Coniferophyta (Conifers)
 Gnetophyta
Ginko
Cycad
Conifers
Cycad Cones (2 male 1 female)
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female pine cone
Male pine cone
Anthophyta (Flowering / fruit plants (250 000 species)
Characteristics
All produce Flowers
All produce seeds that are covered in
Fruit
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STRUCTURE OF FLOWERS
STAMEN
PISTIL
OR
CARPAL
Stamen:
Male reproductive structure
Anther produces the pollen
Filament
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Pistil:
Female reproductive structure
Stigma: sticky tip
Style: connects the stigma and ovary
Ovary: hollow structure that contains the
ovules (developing seed)
REPRODUCTION IN
ANGIOSPERMS
Pollination (grain of pollen falls onto the stigma)
2. Fertilization(takes place in the ovary1.
Once fertilized the ZYGOTE begins to develop into the seeds
embryo)
3.
Fruit development and seed dispersal
(after
fertilization the ovary changes into the fruit)
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Fibrous
root
Tap root
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Definition: a plant’s growth response toward or
away from a stimulus
Three important tropisms
Thigmotropism
• Response to
touch
• Vines coil
due to a (+)
response
Phototropism
Gravitropism
• Response to
light
• Plants have a
(+) response
• Response to
gravity
• Roots have a
(+) response
• Stems have a
(-) response
Hormones:
Chemicals that affect growth and development
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Photoperiodism:
A plant’s response to seasonal changes in
the length of night and day
Short day/long night
Fall flowers
Long day/short night
Summer flowers
Day neutral
Not sensitive to periods of light and
dark Ex: dandylions
Dormancy: period when an organism’s growth or
activity stops
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LIFE SPAN OF ANGIOSPERMS
Annual
complete life cycle in one season
example: impatiens
Biennial
complete life cycle in 2 years
1st year develop roots and short stems
2nd year grow taller, produce flower &
seeds then die
Ex: parsley and celery
Perennials
Live more than 2 years
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