chapter 26
the greening of the earth happened in what eon
phanerozoic
the closest relatives of land plants
charophytes
pros of moving on land
unfiltered sun more CO2 nutrient-rich soil few herbivores or pathogens
cons of moving on land
scarcity of water lack of structural support
land plants are called emybrophytes because
of their dependency of the embryo on the parent
derived traits of plants
alteration of generations
walled spores produced in sporangia
apical meristems
gametophyte
haploid, produces haploid gametes by mitosis
sporophyte
diploid, produces haploid spores by meiosis
nutrients are transferred from parent to embryo through
placental transfer cells
sporophyte produces
spores in their sporangia
sporocytes
undergo meiosis to generate haploid spores
sporopollenin
spore walls contain it making them resistent to harsh environments
gametangia
gamete producing organs
female gametangia
archegonia
male gametangia
antheridia
fungi are
heterotrophs
most common body structures of fungi
multicellular filaments and single cells (yeasts)
filaments form
networks of hyphae
chitin
a strong flexible polysaccharide prevents cells from bursting when they absorb nutrients and water from their environment
hyphae form an interwoven mass called
the mycelium
mycorrhizae
fungal hyphae that form beneficial relationships with plants
2 main types arbuscular mycorrhizal fungi and ectomycorrhizal fungi
arbuscular mycorrhizal fungi
extend hyphae through the root cell walls and into tubes pushing inward of the root cell membrane
ectomycorrhizal fungi
form sheaths of hyphae over the surface of the root and typically grow into root cortex
benefits of mycorrhizae
more efficient than plant roots
fungi reproduces
asexually or sexually
fungal nuclei are usually (hap or dip)
haploid, with the exception of transient diploid stages
plasmogamy
union of two parent mycelia
heterokaryon
when the haploid nuclei from each parent do not fuse right away and coexist in the mycelium
karyogamy
haploid nuclei fuse to produce diploid cells
bryophytes
non vascualr plants
bryophytes
nonvascular plants
3 clades
liverworts mosses hornworts
bryophyte sporophytes grow out of
archegonia
the simplest and smallest sporophytes of all plant groups
bryophytes
sporophyte consists of
a foot a seta and a sporangium or capsule
bryophyte traits
rhizoids
flagellated sperm
reproduction is tied to water
the first plants to grow tall
seedless vascular plants
two clades of seedless vascular plants
lycophytes and monilophytes
ancestors of modern lycophytes grew tall during the
Devonian and carboniferous
formed the first forests
lycophyte ancestors and horsetails
first vascular plants lacked
seeds
mosses and other bryophytes have life cycles dominaed by
gametophytes
seed plants
gymnosperm and angiosperm
2 types of vascular tissue
xylem and phloem
xylem
conducts most of the water and minerals and includes dead cells called tracheids
phloem
consists of living cells and distributes sugars amino acids and other organic producs
water conducting cells are strengthened by
lignin
roots
organs that anchor vascular plants
leaves
organs that increase surface area of vascular plants
2 types of leaves
microphylls and megaphylls
type of leaf that evolved first
microphylls
seed
an embryo and nutrients surrounded by a protective coat
angiosperm
flowering plants
gymnosperms
naked seed plants
seed plants formed in
the carboniferous
ovule
consists of megasporangium megaspore and one or more protective integuments
gymnosperm megaspores have how many integument
1
how many integuments do angiosperm megaspores have
two
microspores develop into
pollen grains, containing the male gametophytes
evolutionary advantage of seeds
a seed develops from the whole ovule
remain dormant until conditions are favourable
can be transported by nature
gymnosperms rose in
the devonian and Carboniferous
appeared early in the fossil record and dominated the Mesozoic terrestrial ecosystems
gymnosperm
cycads
large cone palmlike leaves thrived during the mesozoic not many exist today
conifers
largest group of gymnosperms
evergreens and carry out photosynthesis all year round
flower
angiosperm structure for sexual reproduction
4 types of leaves on a flower
sepals petals stamens carpels
produce pollen
stamens on their anthers
consist of an ovary and a style with a stigma
carpel
where pollen is received
stigma
fruits
a mature ovary
help distribute seeds
angiosperm originated
in the early cretaceous
2 main groups of angiosperm
monocots and eudicots
more than one quarter of angiosperm species are
monocots
more than two thirds of angiosperm species are
eudicots
lichen
a symbiotic association between a fungus and photosynthetic microorganism
millions of photosynthetic cells are held in a mass of fungal hyphae
fungal component of lichen is most often
ascomycete
occupy an inner layer below the lichen surface
algae or cyanobacteria
algae provide what in a lichen
carbon compounds
cyanobacteria provide what in a lichen
organic nitrogen
the growth of forests in the carboniferous resulted in what
drop in CO2 causing global cooling and glacier formation
ergotism
fungi that attack crops and are toxic to humans
fungal infection in animals
mycosis
most of our food comes from
angiosperms
six crops that yeild 80% of the calories consumed by humans
wheat rice maize cassava and sweet potatoes