Plants
Chapter 19 & 20
The origin of plants from algae

Desended from
Charophytes (multicellular
green algae)

Live around edges of
lakes and ponds

Some ancient
charophytes may have
lived in shallow-water
habitats that
occasionally dried out

Natural selection
favored algae that could
survive the dry periods

Adaptations enabled
permanent plant life on
dry land 475 million yrs
ago
What are plants?

Multicellular

Autotrophic

Embryo develops within a mother plant

Eukaryotic
Mosses, hornworts, liverworts
19
2 (phyla) divisions in plants
 1. Bryophytes- do NOT have transport
tissue called vascular tissue, thus are
nonvascular plants
 2. Tracheophytes- do have vascular
tissue, so are called vascular plants
Flowering Plants
Ferns
conifers
Warm-up: (solo on scratch
paper)
 Identify the 2 phyla/divisions of plants
 Identify the characteristic that separates
plants into these 2 divisions
 Identify major examples of plants that
belong to each division
19
Bryophytes

Nonvascular plants grow close to the
ground to absorb water and nutrients.

Seedless plants rely on free-standing
water for reproduction.

Liverworts,
Hornworts
Mosses
19
3 Kinds of Tracheophytes
Pteridophytes :
Gymnosperms
Angiosperms
19
Tracheophyte Facts
Adaptations of
tracheophytes to life
on land
 1. P- protection from drying out
 2. E- exchange of gases through
leaves
 3. T- transport substances
 4. S- support
19
Plants have adaptations that allow them to live on land

P-protection from drying out
 A cuticle allows plants to retain moisture.
 waxy, waterproof layer
– holds moisture in
19
Plants have adaptations that allow them to live on
land.
stoma
E-Exchange of gases on leaves


Stomata are tiny holes in the lower epidermis.
Guard Cells- open & close stoma
Gurard cell
19 Plants have adaptations that allow them to live on
land.

T- Transport by Vascular Tissue
– Xylem: transports water and minerals up from roots to leaves
– Phloem: transports food (glucose) from leaves to roots and shoots
xylem
phloem
water
and
mineral
nutrients
sugars
19 Plants have adaptations that allow them to live on
land.

S- support by cellulose and Lignin
lignin
plant cells
– Allows plants to grow upright
– hardens cell walls of some vascular tissues
– provides stiffness to stems
Bryophytes

Nonvascular plants grow close to the ground
to absorb water and nutrients.

Seedless plants rely on free-standing water
for reproduction.

Liverworts, Mosses, and Hornworts
VIDEO Alternation of Generations: The sex
life of Bryophytes
• What is meant by “Alternation of
Generations”?
• What is the difference between
gametophytes and sporophytes?
www.brainpop.com/science/diversityoflife/seed
19 Tracheophyte #1
lessplants/
Pteridophytes (Club mosses and ferns) are seedless
vascular plants.
Characteristics/Adaptations:
 Vascular tissue
 Seedless
 Ferns, Club Mosses, and Horsetails
Club Moss
Fern
Horsetails
19
Ferns

Sori form under the fronds

Rhizoids

Rhizomes

Fiddlehead
Video
Fern Life Cycle:
• What are Rhizoids
• What is the difference btwn antheridium
and archaegonium?
• What is the function of anteridiogen?
Tracheophyte #2
19
Gymnosperms

www.brainpop.com/science/diversityoflife/seedplants/
Plants that bear seeds that are “Naked” (not enclosed by an ovary)
 can reproduce without free-standing water, via pollination
– ADAPTATIONS
– Vascular Tissue
– Pollen Grains (male
gametophyte)
– Naked Seeds (embryo &
food supply)
– seeds allow plants to
disperse to new places
video
Vascular Plants
19

Gymnosperms do have naked seeds (not enclosed by a fruit).
CONIFERS
CYCADS
GINKGOS
19

Tracheophyte #3
video
Angiosperms (flowering plants)
– Adaptations:
– vascular tissue
– Flowers (reproductive structure)
– Seeds develop within ovaries
– Fruit- ripened ovary
19
Structure of a Flower
Monocots VS Dicots
 Work with your face
partner…
 Create two lists that
describe the characteristics
of monocots and dicots
19
Classes of Angiosperms
1
cotyledon
DICOTS
2
cotyledons
19
Monocots and Dicots (classes of Angiosperms)
lily
Oak tree
grass
Cherry Tree
Fig. 19-5
1. Which group of algae has
been hypothesized to be
the ancestor of plants?
2. Which group of plants
evolved most recently?
3. What main adaptation
separated the
pteridophytes from
bryophytes?
4. In which group of plants
did seeds first appear?