Transcript Bryophites (23.3)

BRYOPHYTES (23.3)
Tasha Fisher and Emily Crawford
What are Bryophytes?
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Include the mosses, liverworts, and
hornworts.
Are the simplest of plants.
About 20,000 species
Found throughout the world, but are
prevalent in moist and shady areas
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Archidium ohioense, a moss
can be found in alpine regions, where
they are subjected to freezing, and
some in deserts, where they are
desiccated most of the time
Many are highly specialized, and
found in restricted habitats
Unique Characteristics
Lack of Vascular Tissue
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Lack vascular tissue
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Gottschelia schizopleura, a
liverwort
must absorb all water and nutrients at the
surface and pass them from cell to cell.
few have modified water transport cells called
hydroids, and a few have solute conducting
cells, called leptoids, but this is rare.
leaves are not true leaves because most species
lack vascular tissue.
Leaves are functionally equivalent to “real
leaves” because they contain chlorophylls a
and b.
“Leaves” are usually one-cell thick, except for
the midrib, which may be up to 15 cells thick.
satisfy their nutritional requirements by
absorbing minerals from dust, rainfall, and
water running over their surface.
Unique Characteristics
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Phaeoceros oreganus, a
hornwort
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Bryophytes are small and the
tallest are 20 cm in height while
the shortest are about 2 cm in
height.
Often grow in prostrate masses or
clumps because they don’t have
any vascular tissues needed for
upright growth.
They do not have roots therefore
they attach to the soil with rhizoids.
Most of them are soft and pliable.
Unique Characteristics
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Survive best in moist habitats but
many can tolerate dry areas by
lowering metabolic needs.
 Also
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Barbula indica,
a moss
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known as desiccating
All mosses, liverworts, and hornworts
have three traits that they share and
that evolved in early plants: a waxy
cuticle, cellular jacket, and large
gametophytes.
If they dry out, they can simply be
revived by water.
Uses of Bryophytes
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Japanese Moss
Garden
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Mosses are used in gardening,
agriculture, medicine, and the
construction of homes.
Other uses for mosses are all-natural
insect repellants, boot liners, and fuel.
Liverworts are sometimes used for
medicinal purposes.
They also very useful in determining any
environmental changes.
Life Cycle of Bryophytes
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Varies among the three divisions
In General….
Sperm is released from the antheridium and uses water to
reach the egg in the archeogonium.
 A zygote forms and undergoes mitotic division until it
develops into an embryo.
 Embryo grows until it becomes a sporophyte in which spores
form.
 The spores are then released and germinate. The spores will
form either male or female gametophytes.
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Life Cycle of Moss