KINGDOM PLANTAE
The World of Plants
What is a Plant: Plant Characteristics
EUKARYOTIC – has a nucleus
MULTICELLULAR– more than one cell
AUTOTROPHIC – can make their own food,
although some can be heterotrophic (i.e. Venus
Fly Trap).
**Food not used for immediate use is
stored in the form of starch**
SESSILE - remains stationary
CELL WALLS made of cellulose
WHAT DO PLANTS NEED TO SURVIVE?
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Sunlight – carry out photosynthesis
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Water & Minerals – Needed to grow
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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:
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Leaves – gather sunlight to carry out photosynthesis
Stems – support the leaves and flowers
Roots – anchor plants to the soil
Flowers – carry out reproduction (reproductive organ)
Vascular Tissue:
- Xylem: transport water & minerals from
the roots.
- Phloem: transport food (sugar/glucose)
from the leaves to the rest of the plant
LEAF STRUCTURE
Cuticle
Upper
epidermis
Mesophyll
Vascular
Bundletissue
sheath
- Xylem
- Phloem
Guard
cells
stoma
chloroplast
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 ADAPTATIONS
CHANGES IN STRUCTURE OR FORM THAT ALLOW
FOR BETTER SURVIVAL IN SPECIFIC
ENVIRONMENTS
CACTUS NEEDLES TO
PROTECT THEMSELVES
FROM HERBIVORES
PINE NEEDLES (REDUCES
WATER LOSS)
Taxonomy of Plants

Plants are divided
into two groups
based on whether
they contain
vascular tissue.
Vascular
Bundles
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Nonvascular Plants
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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.
Moss
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Tracheophytes: contain vascular tissue
 They also contain
seeds.
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Seed-Producing Vascular Plants

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Includes two groups –
Gymnosperms and Angiosperms
Gymnosperms bears seeds on the
surface of cones.
Angiosperms bear seeds within a
protective layer (fruit).
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GYMNOSPERMS
(means “naked seed”)
most common group
is the conifers
Examples: fir, spruce,
cedar, junipers.
CONIFERS: OLDEST SURVIVING
TYPE OF SEED PLANTS. PRODUCE
MALE AND FEMALE CONES.
FEMALE CONE IS WHERE
POLLINATION BEGINS
MALE CONE
PRODUCES POLLEN
GRAINS
ANGIOSPERMS
(“enclosed seed”)
flower bearing plants
Angiosperms
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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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Angiosperms
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Subdivided into two groups –
Monocots and Dicots
Monocots have a single seed
cotyledon
Dicots have two seed cotyledons
Cotyledon: first leaf or pair of leaves
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Monocots
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Parallel venation in
leaves
Flower parts in
multiples of 3
Vascular tissue
scattered in cross
section of stem
Fibrous root
system
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Dicots
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Net venation in
leaves
Flower parts in
multiples of 4 or 5
Vascular tissue in
rings in cross
section of stem
Taproot
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Dicots: Seeds that have two cotyledons
(inc. peas, tomatoes, roses, daisies, etc.)
Functions of Roots:
1. Anchor plants
2. Absorb water & minerals
TAP ROOTS
ABLE TO REACH
WATER FAR BELOW
THE SURFACE
FIBROUS ROOTS
PREVENT THE
EROSION OF TOP
SOIL FROM HEAVY
RAINS.
FLOWERS
The reproductive organ of a
flowering plant
FUNCTION - produce male
(sperm) and female (egg)
gametes & provide a structure
for fertilization.
Designed to attract specific pollinators.
FLOWERS
Flowers are brightly colored
to attract pollinators
Ex: Bees, hummingbirds, bats
FLOWERS
Fruit: wall of tissue enclosing a seed
PARTS OF A FLOWER
Petals
Carpel (female):
Stigma
Style
Ovary
Stamen (male):
Sepals
Anther
Filament
Plant Responses
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Tropism: response of a plant to an
environmental stimulus
Gravitropism: response of a plant to the
force of gravity
Phototrophism: tendency of plants to
grow towards a source of light
Thigmotropism: response of plants to
touch
Plant Responses
Why We Can’t do Without Plants!
Produce oxygen for the atmosphere
 Produce lumber for building
 Provide homes and food for many
organisms
 Prevent erosion
 Used for food
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More Reasons We Can’t do
Without Plants!
Produce wood pulp for paper
products
 Source of many medicines
 Ornamental and shade for yards
 Fibers such as cotton for fabric
 Dyes
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