29 terms

Botany: Bryophytes and Ferns

learning objectives
Distinguish between the bryophytes and ferns
Identify features of the nonvascular plants
Identify features of the seedless vascular plants
Identify features that distinguish plants from algae
Describe the relationship between sporophytes, gametophytes and alternation of generations
Describe ecological and economic roles of bryophytes and ferns
phylum bryophyta:
15,000 species (mosses)
Apical meristem in key resource-finding locations
central spot from which all cells divide, mitosis takes place here
alternation of generation more developed
the moss we see is diploid of haploid?
the visible trend with sporophytes and gametophytes
sporophyte is large
gametophyte is small
diploid or haploid?
sporophyte: diploid
spore: haploid (produced by meiosis)
egg: haploid
sperm: haploid
gametophyte: haploid
compound that makes spore walls tough
sporopollenin...compound that makes them tough
Embryos dependent on female parent plant (similar to placental mammals)
"Embryophytes"...not free living
does algae have embryophytes?
other gymnosperm info
Waxy cuticle that prevents drying
Secondary metabolites (products of pathways that are side branches off main metabolic pathways)...used for defense...algae don't do that!
Bryophytes (liverworts, hornworts, mosses)
location: light but not direct sun, shady, wet, etc
characteristics: bright green, always small
can't transport water any distance, not structure, so they're small
asexual reproduction: little gemma cups of genetic material splashed out
sexual reproduction for gametophytes
palm-tree like structure
archegonium: produce egg
antheridium: produce sperm
MUST BE: submerged in water for sperm to swim to egg
more moss info:
Location: Moist forests and wetlands
Even found in extremely dry climates as long there is water at critical time
"Feathery" or "cushiony"
No vascular tissue (no capacity to transport water)
Small (do you see a connection here?)
Dominant gametophyte
Usually only a few cells thick, with no cuticle
Anchored by rhizoids (root-like structures...no way to absorb water)
all mosses must have _____ for fertilization
once germination begins, a plant must have....
Ecological role of bryophytes
Form microhabitats for animals
Carbon reservoirs in peat bogs store carbon dioxide and help to stabilize global CO2 levels
Ecological "barometers"...mosses very susceptible to toxins/pollution
Economic role of bryophytes
Soil conditioner
Peat is source of fuel
Packing material
Mosses and liverworts in greenhouses...like a weed...can quickly cover flats of seedlings
what about peat bogs make them great for preserving tissue?
seedless vascular plants
Seedless vascular plants (ferns, horsetails, whisk ferns)
support differences between mosses and ferns
moss: center has sclerenchyma and parenchyma for support
fern: xylem and phloem
fern examples, locations, characteristics, life cycles
shady, moist environments
fiddleheads unfurl...
once, twice, thrice pinnate...refers to branching patterns of ferns
Stomata, cuticle, vascular tissue
(aid in providing stable internal water content)
packages with spores inside...distinct and help distinguish between ferns
each sori has millions of sperm
living fossils
like horseshoe crabs, ferns are living fossils...botanical version
are there any ferns native to san diego?
which look least typical of a fern? coffee and cotton fern
sori are used to distinguish with color and pattern
fern life cycle...
fertilization requires water...heart shaped gametophyte