5. Reproductive
structures (such as
those in flowers)
contain spores
and gametes
Leaf performs
photosynthesis
Cuticle reduces water
loss; stomata regulate
gas exchange
Shoot supports plant
(and may perform
photosynthesis)
Surrounding
water supports
the alga
Roots anchor plant;
absorb water and
minerals from the
soil (aided by fungi)
Whole alga
performs
photosynthesis;
absorbs water,
CO2, and
minerals from
the water
Alga
Plant
Figure 16.1
18. Ancestral
green algae
Origin of first terrestrial adaptations
(about 475 mya)
Origin of vascular tissue
(about 425 mya)
Origin of seeds
(about 360 mya)
600 500 400 300 200 100 0
Origin of flowers
(about 140 mya)
Millions of years ago
Angiosperms
Gymnosperms
Ferns and other
seedless vascular
plants
Bryophytes
Charophytes (a group
of green algae)
Landplants
Vascularplants
Seedplants
Seedless
vascular
plants
Nonvascular
plants
(bryophytes)
Figure 16.6
59. Mature
sporophyte
plant with
flowers
Sporophyte
seedling
Germinating
seed
Seed
Seed (develops
from ovule)
Fruit (develops
from ovary)
Embryo
(sporophyte)
Two
sperm
nuclei
Zygote
Endosperm
Embryo sac
(female
gametophyte)
Egg
FERTILIZATION
Key
Haploid (n)
Diploid (2n)
Anther at tip of stamen
Pollen tube growing
down style of carpel
Ovary (base of carpel)
Ovule
Germinated pollen grain
(male gametophyte) on
stigma of carpel
Figure 16.19-6