Chapter 23 Introduction to Plants
1
1.
Autotrophs
2.
Multicellular
3.
Eukaryotes
4.
Cell Wall is made
out of Cellulose
2

Chemical Equation:
Sunlight
◦ CO2 + H2O  C6H12O6 + O2

Sunlight
Word Equation:
◦ Carbon Dioxide + Water  Glucose + Oxygen
3


The common ancestor of ALL plants is thought
to be Green Algae
In the early evolution of plants, they made the
transition from aquatic to land environments
4
*Increased opportunity for
photosynthesis*
Increased access to sunlight
 Increased access to carbon dioxide
Increased opportunity to reproduce and
disperse (spread out)


But, decreased access to water as well…
How did plants overcome that barrier to
successfully colonize on land??
5


Mycorrhizae is a mutualistic
relationship between plants and
fungi to help a plant absorb
water and nutrients from the
soil.
This relationship helped plants
transition to land.
6



Almost all plants have a cuticle covering their
leaves and stems to prevent water loss
The cuticle is waxy (lots of lipids) and holds
water in
The cuticle is also clear to let sunlight in for
photosynthesis
7
8
Once plants colonized land,
certain adaptations allowed
them to reproduce and
disperse their offspring more
effectively—this was the
driving force for the evolution
of plants
9
Gymnosperms
Angiosperms
Evergreens
Flowering
Plants
Seedless vascular
plants
Ferns
Bryophytes
Mosses
Green algae
Evolution of specialized
cells / tissue
Evolution of cuticle
10
1.
Bryophytes (Seedless, Non-Vascular)-Mosses
2.
Seedless, vascular plants- Ferns
3.
Gymnosperms- Evergreens (Pine Trees)
4.
Angiosperms-Flowering plants
11
Mitosis is a type of cell division that makes an
exact copy of the original cell
Can be Haploid to Haploid
Diploid to Diploid
or
Meiosis is a type of cell division that makes
cells with Half the number of chromosomes as
the original cell
Can only be Diploid to Haploid
12

An alternation between two distinct
forms or generations that reproduce
differently

One generation is haploid and
reproduces sexually

The other generation is diploid and
reproduces asexually
13
mitosis
Multicellular
sporophyte
diploid organism
(2n)
meiosis
Unicellular
diploid zygote
(2n)
fertilization
Unicellular
haploid gametes
(n)
Multicellular
mitosis
haploid organism
(n)
Unicellular
haploid cells
(spores)
(n)
mitosis
gametophyte
14
15
By definition,
all plants
alternate
generations
Gametophyte
makes
gametes
n=haploid
Sporophyte
makes spores
2n=diploid
16
Notice that the
more advanced
plants have a
dominant
Sporophyte
The less
advanced plants
have a more
dominant
Gametophyte
17
Gymnosperms
Angiosperms
Seedless vascular
plants
Bryophytes
Green algae
Evolution of specialized
cells / tissue
Example: cuticle
18

Bryophytes

Example: Moss
19
20


They are small and low to the ground because
they do not have vascular tissue
Found only in damp, moist areas on land
◦ 1) Leaves must absorb water for photosynthesis
◦ 2) Sperm swims through water to reach egg
in gametophyte
21
sporophyte
gametophyte
22
Gymnosperms
Angiosperms
Seedless vascular
plants
Bryophytes
Evolution of
vascular tissue
Green algae
Evolution of specialized
cells / tissue
Evolution of cuticle
23

Example: Ferns
24
25

Vascular Tissue
◦
Set of tubes that transport materials around plant
◦
Allows plants to grow taller
◦
Water travels up through Xylem
◦
Sugar/Food travels throughout in Phloem
26
27



Still must live in moist areas
Sporophyte grows successfully with
vascular tissue
But sperm must still swim to egg in tiny
gametophyte
28
29
30
31
Gymnosperms
Seedless vascular
plants
Bryophytes
Angiosperms
Evolution of
pollen grains /
seeds
Evolution of
vascular tissue
Green algae
Evolution of specialized
cells / tissue
Evolution of cuticle
32

Gymnosperms/Angiosperms

Example: Pine Trees or Flowers
33

Examples: Spruce Tree, Fir Tree, Pine Tree
34

Think cones (any conifer like pine trees)
female ovary
male pollen cone
35
tiny
gametophyte
inside cone
sporophyte
Sporophyte Dominates
36



Release a lot, hope some
pollinate
(Meanwhile, irritating
everyone else)
Pollen is the male sperm in
Gymnosperms and
Angiosperms
37

Seeds

Pollen Grains
38



Tough coat protects newly fertilized embryo
Also contains supply of food (endosperm) to
survive during dormancy period
A seed in a gymnosperm is inside the cone
39
40


Plants try to disperse offspring far away so
they have a higher chance of survival.
Dispersal of seeds prevents competition for
water, nutrients, light, and living space.
41
42

Dispersal by wind – wing-like structures,
parachute-like structures
43

Dispersal by animals – fruits have hooks that
cling on animals fur, other fruits provide food
for animals
44


Seeds dispersal is
completed by birds,
small animals, wind, and
water
The tough, fibrous
outer covering of a
coconut provides
protection as well as a
floatation device
45


Hard covering around sperm, light weight allows
travel by wind
Removes water requirement for fertilization
46


At the very end
when pollen lands
on another plant of
the same species
Pollen tube connects
to ovary, fertilizing
egg
47
Gymnosperms
Seedless vascular
plants
Bryophytes
Angiosperms
Evolution of
flowers /
fruits
Evolution of
pollen grains /
seeds
Evolution of
vascular tissue
Green algae
Evolution of specialized
cells / tissue
Evolution of cuticle
48



Think flowers
Most diverse plant group
Most Dominant Plant group
on the planet
49

Flowers
◦ Adapted for pollination by animals
◦ Attract animals to help carry pollen to the next
flower
◦ Color or scent attractors guide animals to obtain
sugar from plant
◦ Some angiosperms still wind pollinate (grass)
50
51
52


Monocots include: grasses, corn, rice, oats,
wheat, orchids, lilies and palms
Dicots include: shrubs, trees (except
conifers) wild flowers and some garden
flowers
53
54
55
56
57


Monocot-pedals in groups of three or multiples
of three
Dicots-pedals in groups of 4s or 5s
58
•Sepals protect the flower
bud from insect damage and
dryness
•The color, scent, and nectar
of flowers attracts insects,
bats, and birds
•These animals help to
transfer the pollen from the
anthers of one flower to the
stigma of other flowerscalled pollination
59
tiny gametophyte
inside bottom of
flower
rest of plant
= sporophyte
Sporophyte Dominates
60
•The Pollen grains are
transferred to the Stigma
where the pollen grain
produces a Pollen tube
•The pollen tube grows down
the style into the ovary where
it fertilizes the ovule
•The fertilized ovule becomes
a seed and the ovary develops
into the fruit of the plant
61
62
63



Typically collects sugar to attract animals
Seeds survive animal digestive system, pooped
out far away from parent (and with free
fertilizer!)
Some are not eaten by animals, just help wind
carry seed
◦ Example: dandelion
64
Gymnosperms
Seedless vascular
plants
Bryophytes
Angiosperms
Evolution of
flowers /
fruits
Evolution of
pollen grains
/ seeds
Evolution of
vascular
tissue
Green algae
Evolution of specialized
cells / tissue
Evolution of cuticle
65



Plants can also reproduce asexually
Vegetative reproduction is faster than sexual
reproduction.
Vegetative reproduction is where many plant
parts can grow to make a whole new organism
when separated.
◦ Examples: Ivy or Potato
66




A division of seed plants that
have only one living species
The leaves of the plant are fan shaped
The Ginkgo is the oldest tree in the
world, once thought to be extinct
Ginkgo’s are the lone survivor of a "family
that existed more than 200 million years
ago" and kept company with the dinosaurs
67
68



The male trees are preferred because female
trees bear a fruit which, after dropping, emits a
foul odor. The fruit is about the size of a cherry
tomato
Roasted nuts from Ginkgo biloba trees have long
been considered a delicacy in their native China.
Treatment for short-term memory loss is just one
of many medicinal uses for the extract derived
from the leaves of Ginkgo biloba trees.
69