Plant diversity lecture

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Kingdom Plantae
What are the evolutionary trends in plants?
What are the reproductive trends in plants?
What constitutes a plant?
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The Netherlands
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29.4 Where is the line dividing land plants from
algae?
Embryophytes Plants with embryos
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What constitutes a plant?
Plants are Multicellular Eukaryotes Photosynth
etic autotrophs Algae may also have these
characteristics. Plants appear to have
developed from algae. Other features that plants
and algae have in common Presence of
chrolophyll b as an accessory pigment Cellulose
cell walls Starch as storage product of surplus
carbohydrates Plants occur both on land and in
water. Algae only in the presence of water.
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Figure 29.7 Some highlights of plant evolution

• Walled spores toughened by sporopollenin
• Multicellular, dependent embryos
• Presence of a waxy cuticle

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29.5. Walled spores produced in
sporangia. Spores are haploid reproductive cells
that can grow into gametophytes (n) by mitosis.
Sporopollenin makes the walls of spores very
tough and protects them against dehydration
Multicellular, dependent embryos Develop from
zygotes that are retained within tissue from the
female parent
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Figure 35.17 Leaf anatomy
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Figure 3.3 Water transport in plants
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Figure 29.5 Alternation of generations a
generalized scheme
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A hypothetical mechanism for the origin of
alternation of generations in the ancestor of
plants
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Figure 29.7 Some highlights of plant evolution
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Table 29.1Ten Phyla of Extant Plants
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Figure 29.3 CharophyceansThe closest algal
relatives of land plantsChara (top),
Coleochaete orbicularis (bottom)
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Chara
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Figure 29.7 Some highlights of plant evolution
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Bryophytes
Liverworts
Mosses
Hornworts
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Figure 29.8 The life cycle of a moss
(Polytrichum)
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Moss life cycle
gametophyte
sporophyte
archegonium
protonema
sporangium
spores
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Marchantia, a liverwort
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Gametangia Archegonium of Marchantia (left),
Anteridium of a hornwort (right)
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A moss sporangium with a spore-shaker tip
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Bryophytes
Liverworts
Mosses
Hornworts
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Sphagnum, or peat moss Peat bog in Oneida
County, Wisconsin (top), close-up of Sphagnum
(bottom left), Sphagnum "leaf" (bottom right)
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A peat moss bog in Norway
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Figure 29.7 Some highlights of plant evolution
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Figure 30.12 Xylem cells in angiosperms
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Seedless Vascular plants- Ferns
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Lycophytes club "moss" (top left)Pterophytes
whisk fern (top right), horsetail (bottom left),
fern (bottom right)
Lycophyta
Pterophyta
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Figure 29.15 Lycophyta and Pterophyta. Artists
conception of a Carboniferous forest based on
fossil evidence
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Figure 29.12 The life cycle of a fern
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Life cycle of a fern mature fern
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Life cycle of a fern sorus
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Life cycle of a fern sporangium
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Life cycle of a fern mature sporangium
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Figure 29.23x5 Life cycle of a fern germinating
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Life cycle of a fern gametophyte
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Life cycle of a fern sporophytes
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Lycophytes club "moss" (top left)Pterophytes
whisk fern (top right), horsetail (bottom left),
fern (bottom right)
Lycophyta
Pterophyta
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Figure 29.12 The life cycle of a fern
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Heterospory The sporophyte has two types of
sporangia that produce two types of
spores, which develop into either female or male
unisexual gametophytes.

• Spores
• Megaspore, developing into a female
  gametophyte, which will produce an egg
• Microspore, developing into a smaller male
  gametophyte, which produces sperm

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Figure 30.2 Variations on gametophyte/sporophyte
relationships
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Figure 30.3 From ovule to seed
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Winged seed of a White Pine (Pinus strobus)