4: Plant Physiology Flashcards
what 4 properties do gas exchange surfaces need to have
permeability
thin tissue layer
moisture
large SA
in the daytime the rate of P will be greater than the rate of R, true or false?
true
(if they were equal there would be no concentration gradient)
what does the upper epidermis do
protective layer
what does the waxy cuticle do
waterproof barrier
what does the palisade mesophyll do
contains palisade cells with chloroplasts
what does the spongy mesophyll contain
air spaces so gases can dissolve
what does the xylem do
transports water and dissolved material
what does the phloem do
transports sugar and amino acids
what does the lower epidermis
protective layer and regulates gas exchange
what do stoma do
small pores allows gas exchange
what do guard cells do
controls opening and closing of the stoma
three tissues in a leaf:
epidermal tissue
mesophyll tissue
vascular tissue
4 factors affecting transpiration
humidity
(light)
temperature
windspeed
4 adaptations in leaf for leaves in gas exchange
waxy cuticle-prevents water loss
air spaces- allows gas movement
spongy mesophyll increases surface area
guard cells- control gas exchange, opens and closes stomata
why is (light) in brackets regarding transpiration
doesn’t affect evaporation, but does effect transpiration, as stomata open at night time
statement about plant transport
loss of water in plant by transpiration from cell walls in leaf cells causes water to be drawn from the xylem vessels by capillary action (adhesion), generating tension, and cohesion ensures this.
what minerals does the xylem transport
transports water and K, Mg and P minerals
what does the phloem transport?
the products of photosynthesis
what adaptations of the xylem are there
1- thick cellulose wall
2- wall strengthened by lignin
3- cells are dead and hollow
4- end walls break down
5-bordered pits allow water columns to bypass blockage
in cose section of a stem, in xylem on the inside or outside
inside
in cross section of a root, where is the phloem
dots around the outside of the star (xylem)
what is the male and female gamete in plant reproduction
pollen male, ovule female
pollination:
pollen from the male part of the plant (anther) is transferred to the female part (stigma) (can happen through wind, insects etc)
fertilization
when the pollen reaches the stigma, to travels down a tube to the ovule inside the ovary. male gamete fuse with female gamete creating a zygote
