BIO Topic 11
plants are
embryophytes
what is am embryophyte
plants that live on land that are embryos are fed before and then become independant
plants are
eukaryotes, multicellular, embryo, photoautorophs, sexual and asexual reporduction
plants develop spores through
meiosis
what are problems plants have living above water
dry environment (plant dry out), gravity (pulls down so need to be strong), atmophere can't bring nutriments to plants (like water easily can), Temperature change(be able to survive shifts)
what are some advantages of plants living on water
better access to direct sunlight, more CO2 in atmosphere than in water, lots of nutriments on shoreline.
what adaptations allowed plants to live better on land
grow to conpentate for nto being able to move, max photosynthesis, protect spores gametes zygote and embryo
what are some key innovations for plants
alternation of gernations, embryo, spores distrobuted through air, stomata, cuticle, indeterminate groth and apical meristem
what is the alternation of generations life cycle (haplodiplontic life cycle)
plants go back and fourth between two stages, sporophyte and has 2 sets of chromosomes and then gametophyte one set of chromosomes (produced gamtes)
what is the embryo
develop embryo thats kept in the maternal gametophte tissues (tissues that protection and nutriments)
spores are portected by what
sporopollenin (polymer forming portective coating around spores)
spores can what in the air
dispers in the air
why is spore disperations good
spread around lots, survive in dryer environements, reporductive success
the caticle is what
protects againts desiccation
what is the stomata
a pore surrounded by protective cellsin leaves and stems, less water regulation and lets gas exchange
what is indeterminate growth
unlike animals plants dont stop growing at a certain size or shape
what is apical meristem
undifferentiated cells at the tip of the plant that can split into multipule kinds of cells, this allows them to keep growing
CLV3 cells at the tips of the plant
slow down cell division and differentiation
the WUS cell
stimultaes differentiation, wants to ddivide cells faster
cell identity depends on
relative cell positioning and the environement (water, light, nutrients)
the CLV3 and WUS cells cause a
negative feedback loop
mutation sin CLV3 make
cells divide more than usual, larger stem size, more flowers and larger fruits
mutations in WUS gene causes
makes iregular shoots and few or defective flowers
example of a non-vascular plant
bryophytes
what is a bryophyte
paraphyletic group of non-vascular plants, don't make seeds or flowers
what does non vascular mean
no specialized tissues for transporting water and nutriments
byrophytes have life cycles that are dominated by
gametohpytes, no vascular system and cell swimming depends on water
what is a rhizoid
a filament that attaches to a substrate, in life cycle of bryophyte
type of vascularization plant
tracheophytes
what is a tracheophyte
monophyletic group of vascular plants
what do tracheophytes have
a life cycel dominated by the sporophte and the gametophyte is smaller
what is vascularization
presence of tissues that transport mineral, water and nutriments
what are the two types of specialized transport tissues in vascularization
Xylem and phloem
what idoes xylem do
transports water and minerals to leaves
what does phloem do
transports sugars, products of photosythesis (more on the outside)
what is a lignin
polymer cell wall, for support from gravity, spread further and get more light
leaves specialize in
producing spores
homosporous is when
leaves have only 1 kind of spore that produces bisexual gametophytes, (produces M and F at the same time, and in most seedless vascular plants)
heterosporous is when
leaves have 2 types of spores which produce either a M or F gametophyte (in all seedless plants)
what are advantages of heterospory
theres specific function for the specific sex of the spore (can perform better), seperate gametophyte can better nourish the embryo, M and F can mature at different times (reduced chances of self fertilization)
what is a spermatophyte
seed plants
what is a seed
an embryo surroudned by a protective coat and nutriments
innovation of seed plants
really small gametophyte is protected from environement, UV and desiccation and nurished by sporophyte
what are the five key innovations of seed plants
small gametophyte, ovule, heterosporous, pollen grain and make seed
what does the ovule do
structure that has the megaspore, fertilizes without water form the environement
whats a microspore
male gametophyte, can sprad further
whats a megaspore
female megaspore, nurishes and makes embryo
whats the pollen grain
male gametophyte surrounded in a pollen wall, go very far
why is the production of a seed important
better survival of plants during reporuction, embryo well noursihed and can resist drought and low temperatures, adapts to new environements and seed germinations during favourable conditions
what is a gymnosperm plant
produces seeds (without enclosed chamber) but no flower
these exposed seeds can survive tough conditions
evolved to climate,
gynosperms have sperm with no
flagellum
what is an angiosperm
flowering plants that produce seeds in chambers (ovaries) (90% of living plants)
angiosperms have enclosed seeds that
mature into fruit
a flower is a
modified leaf good for reporudction
a fruit is a matured
ovary of a flower that helps seed spread
what is anemochory
seed dispersale by wind
what is zoochory
seend dispersal by animals
what is crosspolitnation
doubler fertilization, one sperm cells fertilizes the egg (zygote) and the other sperm cell fuses the nuclei of the central cell (endosperm)
ovules mature into
seeds