The document discusses plant structures and classification. It describes how flowering plants are divided into monocots and dicots based on having one or two cotyledons. Monocots typically have parallel veins, scattered vascular bundles, petals in multiples of three, and herbaceous or woody stems. Dicots usually have netted veins, vascular bundles arranged in a ring, petals in multiples of four or five, and contain the majority of trees and flowers. The document outlines the structures and functions of leaves, stems, and roots.

1. Plant
structures

2. PLANTS
Angiosperms
-Divided into two groups:
monocots and dicots
The names come from
parts of the embryo in the
seed
Radicle = embryonic root
Hypocotyl = embryonic
stem
Cotyledon = seed leaf
(may have one or two)
Classifying plants

3. PLANTS
Angiosperms: Monocots
Monocots – contain one cotyledon (ex.
corn)
→Two types:
“Woody” stems (tough and rigid)
About 10% of all monocots
i.e. Bamboo, palm trees
Herbaceous stems (soft and fleshy)
i.e. Orchids, tulips, grasses, wheat
Classifying plants

4. PLANTS
Angiosperms: Dicots
Dicots – contain two cotyledons
(ex. Beans)
Ex. Most of Canada’s native trees,
many wildflowers, tomatoes,
lettuce, yams, beans, etc.
Classifying plants

5. PLANTS
Monocots vs. dicots

6. PLANTS
Monocots vs. dicots

7. PLANTS
Monocots vs. dicots
Monocot leaves Dicot leaves
Parallel-veined leaves Net-veined leaves

8. PLANTS
Monocots vs. dicots
Monocot stem Dicot stem
Primary vascular bundles scattered Primary vascular bundles in a ring

9. PLANTS
Monocots vs. dicots
Monocot flower Dicot flower
Petals: multiples of 3 multiples of 4 or 5

10. PLANTS
Monocots vs. dicots

11. PLANTS
Angiosperms: Reproduction
-Flowers are used for reproduction
-Usually colourful and attractive to
attract animals
-Animals visiting flowers to collect
nectar or pollen assist with
pollination
-pollination = transferring of pollen
from male to female plant
- Flowers adapt to pollinators (i.e.
shape, scent)
Classifying plants

12. PLANTS
Angiosperms: Reproduction
Stamen – “male” reproductive
organ (produce pollen)
Carpel – “female” reproductive
organ (produce ovum)
Classifying plants

13. PLANTS
Angiosperms: Reproduction
Seeds and Fruits
-Flowering plants are
sporophytes (2n)
-The pollen and ovum that they
produce are gametophytes (1n)
-The seed is the result of
fertilization.
-After fertilization, the ovary
walls in the flower swell, become
fleshy, and form either the fruit
or seed pod
Classifying plants

14. PLANTS
Gymnosperm vs. angiosperm
Classifying plants

15. PLANTS
The Leaf:
The main role of the leaf is
to convert solar energy into
chemical energy through
photosynthesis.
Parts of the Leaf:
Epidermis
Stoma
Spongy Layer
Vascular Tissue
Palisade cells
Structures

16. PLANTS
The Leaf: Epidermis
Cuticle
-waxy non-living exterior that
allows for water proofing
-to protect their interior
tissues
-composed of cells tightly
packed together.
The cuticle is so effective, it
can also block the passage of
gases through the cells of the
epidermis.
Structures

17. PLANTS
The Leaf: Epidermis
Cuticle
So how does CO2 and water
molecules needed for
photosynthesis enter the
leaf?
Through the stoma
Structures

18. PLANTS
The Leaf: Epidermis
Stoma (Greek for “mouth”)
-pore-like openings in the
plant’s epidermis
-function – to permit gas
exchange between the leaf’s
interior and external
environment.
-The larger the opening, the
faster the gas exchange
-The size of the opening is
controlled by two guard
cells.
Structures

19. PLANTS
The Leaf: Epidermis
Stoma and Guard Cells
Structures

20. PLANTS
The Leaf: Spongy Layer
-Where water is stored.
-Water vapour will be
released through the
stomata in a process called
transpiration.
Structures

21. PLANTS
The Leaf: Vascular
Tissue
The VEINS – made up
of xylem and phloem
which are bundled
together in thin strands.
They allow the
movement of water and
nutrients
Think back to the veins
in a dicot and monocot
flower. Which veins are
parallel and which are
net-like?
Structures

22. PLANTS
The Leaf: Palisade Cells
-Palisade cells act like a solar
panel.
-In dicot leaves, the palisade
cells stand tall and upright.
-The top end of the palisade
cell’s surface is exposed to
light.
-The bottom end is exposed
to the gases in the spongy
layer.
-This allows photosynthesis
to take place by chloroplasts
Structures

23. PLANTS
The Leaf: Outer
characteristics
-the stalk that attaches the
leaf to blade to the plant
stem is the petiole
Structures

24. PLANTS
The Stem: Epidermis
-Outermost layer of the stem
-Contains chloroplasts,
cuticle, stomata
-Allows for photosynthesis to
take place
-Also protects the inner
tissues of the stem
Structures

25. PLANTS
The Stem: Vascular Tissue
-Contain both xylem and
phloem
-In dicots, the tissue is
arranged in a ring
-In monocot, the tissue is
scattered everywhere.
Structures

26. PLANTS
The Stem: Pith
-Found in the center of the
stem
-Contains air spaces (spongy
tissue)
-Stores water and some
nutrients.
Structures

27. PLANTS
The Stem: Cortex
-Layer of tissue surrounding
the pith.
-Rigid tissue
-Structural support
-Also stores water and some
nutrients
Structures

28. PLANTS
The Roots:
-Anchors the plant in the soil
and holds the stem in place
-Prevents erosion
-Roots absorb water required
for photosynthesis and replace
water loss during transpiration.
-Absorb dissolved minerals
-Store starch that is made by
the leaves
Structures

29. PLANTS
The Roots: 2 types
Fibrous Roots – large number
of slender roots
Taproot – one large root.
Ex: Beets, carrots, turnips and
radishes.
Which type of root is more
effective in preventing erosion?
Structures

30. PLANTS
The Roots: 4 zones
-Zone of maturation: cells
differentiate into different
types of cells.
-Zone of elongation: allows
the root to get deeper within
the soil
-Meristematic region: rapid
mitosis of undifferentiated
meristematic cells.
-Root cap: protects the
meristematic region.
Structures

31. PLANTS
The Roots: Epidermis
-Contain root hairs on the
surface.
-Protects the interior root
structures.
-Absorbs water and dissolved
minerals from the soil.
Structures

32. PLANTS
The Roots: Epidermis
-Roots epidermal cells have no
chloroplasts therefore they
cannot make food.
-The root cells must perform
cellular respiration (what
humans use) in order to
stay alive.
-The GLUCOSE comes from the
starch in the cortex of the
root.
Structures
C6H12O6 + 6O2  6CO2 + 6H2O + energy

33. PLANTS
The Roots: Cortex
Lies inside the root’s epidermis
Contain vacuoles for food
storage
The purple colour observed in
photographs is the starch
that is stored in the
vacuoles.
(purple is the dye that was
used)
Structures

34. PLANTS
The Roots: Endodermis
-Inside the cortex
-Carefully filter materials travelling
into the center of the root.
- Filtering stops harmful
substances from entering the
plant.
-It has a selectively permeable
membrane. It only allows certain
molecules to pass through.
-Therefore the root
endodermis, determines what
enters the entire vascular system
for transport to the rest of the
plant.
Structures