lecture 4 Flashcards
what is another name for vascular plants
tracheophytes
besides the bryophytes all other land plants have
vascular tissue
vascular plants have what as the dominant phase
sporophyte
bryophytes have what as the dominant phase
gametophyte
plants can produce many
sporangium and gametophytes
what is a consequence to have a large/tall sporophyte in a heterogenous environment
they have to develop a new way to transport h20 and nutrients
what happens to the plant in the air
light can be used to make glucose but water is limiting
what happens to plant in soil
water is abundant in the soil but no light and tissues still need food
leaves do what
make sugars by photosynthesis
stem does what
support the plant to elevate the leaves and maximize photosynthesis
roots do what
absorb water and nutrients
what does the vascular tissue do
conducts water and minerals from the roots up to the top of the plant and it conducts sugars from leaves to the lower parts of the plant
what direction does xylem go
up
what direction does phloem do
down
the xylem tissue is made up of
tracheids
what are tracheids
long xylem cells full of holes called pits and DEAD AT MATURITY
the xylem is strengthened by
lignin a complex polymer
flowering plants have what cells that accompany traceids
vessel cells
what does xylem carry
water and minerals
what does phloem carry
phloem sap and its mostly sucrose
the phloem cell are what
called sieve cells and they are alive at maturity
sieve cells
have no organelles and depend on other cells for metabolism
where does phloem start
around the xylem
does xylem or phloem use energy to move its items
only phloem uses energy to move things
explain phloem pressure flow
- source cell uses active transport to push sugars into sieve cell reducing heir solute potential 2. water is taken by xylem by osmosis raising pressure in sieve. 3. resulting pressure differences drives sugars along the sieve tube into sink tube 4. sucrose is unloaded in sink cell 5. water moves back to the xylem by osmosis
deposition of coal deposits come from what period
carboniferous period
what are lycophytes
have independent sporophyte and gametophyte, true dichotomous branching roots, have leaf like structures called microphylls
lycophytes have their sporangia where
in strobili
where do lycophyte gametophytes fertilize
underground
microphylls
not true leaves, small leaf like with one vein
most vascular plants are what
heterosporous
heterosporous
have two different spores of different sizes and sexes
megaspore
develops into a female gametophyte (megagametophyte)
microspore
develops into male gametophyte (microgametophyte)
where is homospory found
in byrophyes, some lycophytes and most ferns
homospory
where one type of spore is made by meiosis and only one gametophyte is made
what is the ploidy of mega/microsporangium
2n
what is the ploidy of mega/microspore
n
