Transcript Seedless Non-Vascular Plants The Bryophytes

Saturday, April 9, 2016
SEEDLESS NON-VASCULAR
PLANTS
THE BRYOPHYTES
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Packet #69
Chapter #29
Review Book pg #131
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THE BRYOPHYTES
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Features That Distinguish Bryophytes From
Green Algae and Other Plants
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BRYOPHYTES
Bryophytes Diversity
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Figure 29.9
Page 582
Bryophytes include the
mosses, liverworts and
hornworts
Seedless plants that
disperse via haploid
spores
Have several
adaptations that green
algae, a protist, lack.
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Cuticle
Stomata
Multi cellular
gametangia
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BRYOPHYTES II
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Additionally, bryophytes are non-vascular plants.
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Non-vascular plants lack vascular tissue, xylem and
phloem, and limits them to moist environments a to
small size
Bryophytes are the only plants with a dominant
gametophyte generation.
Most of the life cycle is spent in the gametophyte
generation.
 Sporophytes, when developed, remain permanently
attached and are nutritionally dependent on the
gametophyte.
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THE “EVOLUTION” CONNECTION
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The evolution of bryophytes is based on fossil
evidence of ancient plants and on structural and
molecular evidence
However, the fossil record is very incomplete
 Bryophytes may represent a side-line in evolution
 Hornworts, a type of bryophyte, may be the most
ancient based on structural and molecular evidence
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BRYOPHYTES
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Phyla of Pryophytes
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PHYLUM BRYOPHYTA
THE MOSSES
Bryophytes have been
distributed around the
world from the tropics to
the arctic.
They can exist in dry or
cold habitats
They can practically
desiccate
 Rehydrates following
rain events.
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One wetland moss,
Sphagnum, forms
extensive deposits of
peat.
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PHYLUM BRYOPHYTA
THE MOSSES
The mosses are
colonial plants.
 They have rhizoids
that anchor the plant
in the soil.
 They lack true leaves,
roots and stems
 Alternation of
generations is
present.
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Saturday, April 9, 2016
PHYLUM BRYOPHYTA
THE MOSSES
Some mosses have
separate sexes; while
others bear both
archegonia (female)
and antheridia (male)
on the same plant
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Steps 1 – 3
Page 581
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Figure 29.8
Page 581
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PHYLUM BRYOPHYTA
THE MOSSES
Bryophytes have
gametophytes that are
green plants that grow
from a filamentous
protonema.
The protonema is a
green filamentous
growth that arises from
spore germination and
eventually gives rise to a
mature gametophyte.
 Found in liverworts and
mosses
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Step 4 - 7
Page 581
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Flagellated sperm are
transported to the
archegonia by splashing
raindrops and swim to the
archegonia where they
fertilize the egg
Diploid zygote grows into a
multicellular sporophyte
Diploid sporophyte,
attached to the
gametophyte (archegonia) ,
grows as it receives
nutrition.
Figure 29.8
Page 581
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PHYLUM BRYOPHYTA
THE MOSSES—REPRODUCTION I
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Step 8
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Figure 29.8
Page 581
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PHYLUM BRYOPHYTA
THE MOSSES—REPRODUCTION II
The mature sporophyte
undergoes meiosis to
produce haploid spores
Spores are dispersed by
wind.
Spore germinates. Grows
into a protonema that
forms a bud.
Protonema develops into
the haploid gametophyte
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The dominant stage.
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Gametophyte
Sporangium
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LIFE CYCLE OF THE MOSSES
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Sporangium
Mature Sporangium
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LIFE CYCLE OF THE MOSSES
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Germination
Gametophyte
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LIFE CYCLE OF THE MOSSES
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BRYOPHYTES—PHYLUM
HEPATICOPHYTA
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The Liverworts
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Have gametophytes
that are leafy or
flattened, lobelike
thalli.
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PHYLUM HEPATICOPHYTA
THE LIVERWORTS
The plant body is not
differentiated into
roots, stems and
leaves—similar to
what is seen in some
algae, fungi and
similar simple
plantlike organisms.
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Liverworts have a
dominant
gametophyte
generation.
 Reproduction is
similar to that of the
mosses.
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PHYLUM HEPATICOPHYTA
THE LIVERWORTS
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BRYOPHYTES—PHYLUM
ANTHOCEROTOPHYTA
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The Hornworts
Have thalloid
gametophytes
 Hornworts resemble
liverworts but may
not be closely related
to them.
 The sporophyte, that
develops after
fertilization, forms a
“horn.”
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PHYLUM ANTHOCEROTOPHYTA
HORNWORTS
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REVIEW
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Students
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List potential examination questions and/or here, and
on following slides, based on the packet.
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REVIEW
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