Plant systems Flashcards
(25 cards)
leaves are structurally ___ to enable them to ____ function
adapted, effectively
structural features needed by a leaf
- ____ surface area
- ___: surface for gas exchange w/ environment
- cells that contain ____ and chlorophyll
- ____transport system
-____ transport system
large, pores, chloroplast, water, food
waxy cuticle
- ___ layer that covers the surface of all leaves to ____water loss
waxy, reduce
epidermis
- ____ cell layer thick
- upper epidermis: exposed to ___ sunlight
- lower epidermis: ____ cells allowing for ___ exchange
one
direct
specialised
air
palisade mesophyll
specifically designed for ___;
___ cells of palisade contains many ___; main photosynthetic cells
photosynthesis
columnar
chloroplasts
spongy mesophyll
rounded cells with ____ chloroplasts
cells are ____ packed, separated by larger, ___ spaces
closely associated with ____ for diffusion of ___
fewer
loosely, airier
stomata, gases
stomata
each individual ___or stoma, consists of a small ____ between a pair of specialised cells known as ____ cells
by modifying ___of stomata, guard cells regulate ___ exchange
pore, opening, guard
size, gas
vascular bundle/vein
xylem: transports___ and ___ from __ to leaves
phloem: transports ____ products from leaf to __ __ __ __
water and minerals; roots
photosynthetic, other parts of cell
horizontal orientation of leaves
___ surface facing sun; lower surface facing ____
tissue distribution is ____ on upper+lower sides
known as ___ leaves
upper, shade
different
dorsiventral
vertical orientation of leaves
___ sides exposed to the sun
tissue distribution is the ___ on both sides
known as ____ leaves
both
equal
isobilateral
main functions of stomata:
- uptake of CO2
- limit loss of water
why do stomas open in the day and close at night?
in the day, there is light for photosynthesis to occur, so stomas open
in the night, there is no light for photosynthesis to occur, so stomas close to prevent water loss
guard cells opening:
guard cells fill with water to become ___
thin outer layers ____ outwards
thicker inner layers do not ___ so they are pulled ___ and the pore ___
turgid, stretch, bulge, apart, widens
guard cells closing:
stomates __ water, outer walls no longer ___, inner walls move together to ___ the gap
loses, bulge, close
external factors influencing stomatal behaviour (4)
light, humidity, soil water status, air temp, atmospheric CO2 concentration, salinity
xylem:
long ___-living tube that runs from the ___ to the ___
water is ___ by the root hairs and then undergoes cell to cell ___ until it reaches the xylem
water then transported through xylem to the leaves until it is ____ through _____
non
root
leaves
absorbed
movement
evaporated
transpiration
what does the lignin do?
reinforces xylem and prevents it from collapsing
what do the fibres in the xylem do?
support xylem tissue
what do the pits do in the xylem?
allow the movement of water
phloem
____ vascular tissue that is responsible for transporting ____ products to ___ parts of the plant
process of transportation known as ____
conductive cells/sieve elements: helps in the ___ of food throughout the plant
parenchyma cells- ____ cells for ___
- these are called ___ and albuminous cells
supportive cells- ____ and sclereids
____ cell walls to make them ____ and have a higher ___ strength
living, photosynthetic, all
translocation
conduction
unspecialised, storage
companion
fibres
secondary, rigid, tensile
transpiration
loss of water from the plant through ___ at the leaf surface– main driver of water ___ in the xylem
water pulled __ by this tension
at night, the stomata closes, so there is no transpiration, thus water is held in stem in leaf by ____ forces and ____ forces
evaporation
movement
up
adhesive
cohesion
what is the rate of transpiration affected by?
temperature and light
adhesion forces: ___ between water and ___ walls
cohesive forces: ___ of water molecules to ___ ___
attraction, xylem
attraction, to each other
translocation
sugars move from ___ where they are produced to ___ where they are needed for growth
sources
sinks
