Download NONVASCULAR PLANTS

BY:
D. GAGON
S. NGUYEN
H. HAYASHI
• Non vascular plants do not have a vascular system
• These plants do not have the xylem and phleom
• Xylem: conducts water and dissolves nutrients
• Phleom: conducts sugar and other metabolic products
• Produces energy through photosynthesis (occurs at the top off
the plant)
• Do not have real leaves.
stems, roots
• Obtain water by living in
moist places
• Distribute water through
capillary actions,
diffusion, cytoplasmic
streaming
• Morphological characteristics of non-vascular plants include
protonema, gametophores, rhizoids, archegonia, antheridium, and
three parts to the sporophyte which include the foot, seta, and
sporangium.
• Protonema: branched, one-cell filaments that sprout from
germinating moss spores. Each one will sprout one "bud"
which will form into a gametophore.
• Protonema plus one or more gametophores equals a
gametophyte
• Gametophore: gamete-producing structure
• Rhizoids: the "root" system of a gametophyte that only serves
as an anchor and is not used in water or mineral obtaining
processes
• Archegonia: eggs are produced here and wait for sperm
• Antheridium: sperm producing structure (on gametophore)
• Sporophyte
• Foot: absorbs water and nutrients from the gametophyte.
• Seta: the stalk which transports materials to sporangium
• Sporangium(capsule): produces spores through meiosis
which are released
• Peristome: upper part of capsule that open under dry conditions
and closes when wet
• Hornwort and Moss sporophytes both have stomata
• Alteration of generations
• Pt I: Gametophyte
• Male plant makes sperm in the antheridium through mitosis
• Female plant makes eggs in the archegonium through mitosis
• Water brings sperm to the egg where they fuse to create a dipliod
zygote which grows into a sporophyte
• Pt II: Sporophyte
• Sporophyte grows on the mother until it cracks and a stem grows out
with a calyptra cap on top
• The capsule under the calyptra releases the spores (asexual)
• Special case of Liverworts
• Can produce asexually through…
• Fragmentation: the breaking off of a fragment of the plant which
lands to become a separate, independent plant
• Gemmae cups: gemmae is tissue which grows in the cup and
when overflowed with water, cells land and form new liverwort
plants
• The gametophyte stage is dominant
• The sporophytes grow from and are dependent on
gametophytes for the water and nutrients to perform
photosynthesis in the top of the plants
• Green algae (protist): the most recent ancestor to nonvascular
plants and vascular plants
• Vascular plants branched off when sporophyte evolved to
become dominant in the life cycle
• Speciation occurs between plants with the development of
seeds, seed within fruit, flowers, and leaf modification
• Overtime, development of root-shoot-leaf axis and vascular
system (xylem and phloem)
• Nonvascular plants are oldest plant at 475 million years old
• Oldest of the bryophyta (moss, liverwort, hornwort) plants is
believed to be the liverwort
• Molecular, physiological, and genetic data describes
nonvascular plants as oldest
• Limited to environments high in moisture/water, have spores not
seeds
• The necessity of water shows they derived from an underwater
environment such as the green algae (common ancestor)
• Some fish and other species eat these non-vascular plants
• It provides insects with habitats
• It can live on trees and if it gets extra water it can give that to
the tree
• Many Bryophyte species regulate various gases and minerals
both in soil and in the atmosphere
• Peat moss (moss genus Sphagnum) is a prime example of an
atmospheric gases regulator
• Due to phenolic compounds (similar to alcohol) peat moss does not
readily decay after death and it has large empty cells that trap large
amounts of CO2
• Estimated at 400 billion tons of organic carbon is stored in
peat
• Overharvesting can contribute to global warming
• Also due to the fact that peat moss does not decompose readily, it
provides a unique wetland environment that is home to many types of
bacteria that only grow in peatlands.
• Peat Moss has been a readily used fuel source in much of
Europe, Asia, Ireland, and Canada.
• 90% of the world's peat moss comes from areas in and around
Canada which contributes to their economy
• It is also commercially used as a soil conditioner.
• Peat moss has recently started to be used in horticulture as a soil
conditioner which can lower the Ph of the soil to allow for better
growth of plants that require a lower Ph.