Land Plants Flashcards
sporopollenin
a layer of durable polymer that prevents exposed zygotes from drying out in charophytes
what did the movement onto land by charophyte ancestors provide
unfiltered sun, more plentiful CO2, nutrient-rich soil, and fw herbivores or pathogens
Challenges of the move onto land
scarcity of water, lack of structural support
Four key traits that appear in nearly all land plants but are absent in the charophytes
Alternation of generations (with multicellular, dependent embryos)
Walled spores produced in sporangia
Multicellular gametangia
Apical meristems (linear growth from root and shoot tips)
Cuticle
provides protection and controls moisture loss
Secondary compounds
defense against herbivory and UV protection
Nonvascular plants
Bryophytes, Liverworts, Hornworts, Mosses
Phylum Hepatophyta
Includes liverworts
phylum Anthocerophyta
includes hornworts
phylum bryophyta
includes mosses
Vascular plants
seedless
seeds
gametophyte
haploid, produces haploid gametes by mitosis
Sporophyte
diploid, produces haploid spores by meiosis. Produced by fusion of the gametes
where is the diploid embryo retained
within the tissue of the female gametophyte
placental transfer cells
nutrients are transferred from parent to embryo through these
embryophytes
land plants, called this because of the dependency of the embryo on the parent
haplodiplontic life cycle
Multicellular diploid state - sporophyte
Multicellular haploid stage - gametophyte
Multicellular diploid stage - sporophyte
Produces haploid spores by meiosis
diploid spore mother cells (sporophytes) undergo meiosis in sporangia
produce 4 haploid spores
first cells of gametophyte generation
Multicellular haploid stage - gametophyte
spores divided by mitosis
produces gametes by mitosis
gametes fuse to form diploid zygote
first cell of next sporophyte generation
Gametangia
organs that produce gametes
archegonia
female gametangia
produce eggs and are the site of fertilization
antheridia
male gametangia
the site of sperm production and release
what grows out of archegonia
bryophyte and sporophytes
are the smaller and simplest sporophytes of all extant plant groups
what does a sporophyte consist of
a foot, a seta (stalk), and a sporangium
Another word for sporangium
capsule
what does the capsule do
discharges spores through a peristome
hornwort and moss sporophytes have a _______ for gas exchange
stomata
stomata
openings in the surface of the plant controlled by two cells
all plants but liverworts have them
control CO2 gain and H2O loss
Hornworts
Earliest fossils are cretaceous so origin is a mystery
about 100 known species
peat
sphagnum, or “peat moss”, that forms extensive deposits of partially decayed organic material known as peat
_______ is an important global reservoir of organic carbon
sphagnum
