Transcript Plant Unit: part 1

Algae
Autotrophic protists
Unicellular and multicellular Aquatic
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Multicellular algae much like plants
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Five phylaVolvox
1.
Chrysophyta (golden)
2.
Pyrrophyta (fire)
3.
Rhodophyta (red)
4.
Phaeophyta
(brown)
5. Chlorophyta (Green) –
Modern plants believed
to evolve from this algae
Spirogyra
Alage
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K
E
L
P
Algae are very commercially useful
Used to thicken everything from toothpaste to ice
cream
Kelp harvested every day on California coast
Can grow a foot a day!! Can be 60 meters long!
Plantae
Try to live without them!
Plants
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Autotrophic- produce food through photosynthesis
multicelluar
Have cell walls made of cellulose
eukaryotic
Green
Non motile
Limited communication
Cuticle- waterproof coating
with pores called stomata
Adapted from green algae
for life on land
Oldest and Biggest
Bristlecone Pine
Giant Sequoias
Taxonomy
Monocots Dicots
Bryophytes- Non Vascular Plants
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Non vascular - must transport water and nutrients by
diffusion and osmosis as a result they have limited size
and live in moist climates
Like all plants they exhibit alternation of generations but
gametophyte is the dominant form
Three classes: Mosses, Liverworts and Hornworts
(wort – Early English for plant)
Moss
Capsule
Alternation of Generation
Alternation of Generation
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Archegonium-the “female” gamete producing structure
Antheridium- the “male gamete” producing structure
Gametophyte- haploid plant that produces gametes
Sporophyte- diploid plant that produces spores
Moss life cycle
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Mosses are
pioneer plants
Sphagnum
moss forms
peat bogs source for peat
moss and coal
from ancient
bogs
Tracheophytes
Vascular plants
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Vascular system found in all three
structures roots, stems and leaves
Xylem is the vascular tissue that
transports water and minerals up
from the roots
Phloem is the vascular tissue that
carries sugars and organic materials
from the leaves where they are
produced
In vascular plants the sporophyte is
the dominant generation
Seedless Vascular Plants
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Without seeds these plants reproduce sexually in moist
environments
Psilophyta- whisk ferns
Sphenophyta- horsetails
Lycophyta- club mosses
Pterophyta- ferns
Club Moss
Ferns
Seed plants
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Seeds allow plants to develop in
unfavorable conditions reproduction
doesn’t rely on moist environments
There are two types of seeded plants
 Gymnosperms produce their seeds in
cones and generally keep their leaves
all year
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Angiosperms produce flowers, bear
their seeds in fruit and in general lose
their leaves annually
Gymnosperms
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Means “naked seeded”
About 700 species
Conifers (cone bearer)
by far the biggest group
(pines, spruces ,firs,
cedars, redwoods)
Cycads ruled long
ago,but today only 11
genra remain
Ginkgoes are also living
fossils, only one species
remains
Angiosperms
Angiosperms are
flowering plants
 Of 250,000vascular
plants 235,000 are
angiosperms
 Seeds enclosed in fruit
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classified by the number
of cotyledons in their
seeds:
Monocots- one cotyledon
Dicots- two cotyledons
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Angiosperms
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Monocots and dicots also have other distinguishing
characteristics
 Most woody plants are dicots
 Most herbaceous plants are monocots
Cotyledon. The first leaf or one of the first pair or
leaves developed by the embryo of a seed plant