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Plants I
Chapters 29
What you need to know!
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Why land plants are thought to have evolved from
green algae.
Some of the disadvantages and advantages of life on
land.
That plants have a unique life cycle termed alternation
of generations with a gametophyte generation and a
sporophyte generation.
The role of antheridia and archegonia in
gametophytes.
The major characteristics of bryophytes.
The major characteristics of seedless vascular plants.
Domain: Eukarya
Kingdom: Plantae
 Bryophytes (non vascular): hornworts,
liverworts, mosses
 Tracheophyta (vascular):
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Seedless plants – horsetails and ferns
Seed plants
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Class - Gymnosperms (naked seeds, flowerless): Ginko
and Conifers
Class – Angiosperm (seeds, and flowers): monocots
and dicots/eudicots
Characteristics
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Multicellular
Eukaryotic
Photoautotrophic
Cell walls made of cellulose
Peroxisomes to recover molecules from
photorespiration
Stomata for gas exchange
Alternation of Generations
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Sporophytes (2n)
 gametophytes
(n)  back
Increasingly
(evolution)
dominated by
sporophytes
Heterosporous: a
few large, sessile,
female spores and
many small motile
male spores
Bryophyta
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Phylums:
liverworts,
hornworts, and
mosses
Terrestrial but
close to water
Seedless (spores)
Non vascular
Small
Rhizoids – root
Bryophyte Reproduction
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Dominant gametophytes
Sporophyte grows on
top of fertilized female
gametophyte
Heterosporous:
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Male gametophyte –
antheridium produces
spermlike spores that
swim (through water) to
the egg
Female gametophyte –
archegonium containing
female spore (egg)
Tracheophyta – Seedless Plants
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Horsetails and Ferns
Vascular Plants – vessels
transporting liquids
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Xylem for H2O
Phloem for sugar and nutrient
transport
Lignified cells – lignin
strenghtens cell walls
Sporophyte dominant life
cycle
Roots for anchorage and
absorption of water and other
nutrients
Heterosporous