topic 6 - plant structures and their functions Flashcards
how is the function of the xylem adapted to its job in a plant?
lignified dead cells in xylem transporting water and minerals through the plant
how is the function of the phloem adapted to its job in a plant?
living cells in phloem using energy sucrose around the plant
how are water and minerals transported through a plant?
transpiration
what is the function of stomata?
controlling gas exchange in a leaf of a plant
what is the stomata?
a pore in the leaf surrounded by guard cells
how is sucrose transported around the plant?
translocation
how is the structure of a leaf adapted for photosynthesis and gas exchange?
have a large surface area and contain openings called stomata to allow carbon dioxide into the leaf and oxygen out
how does light intensity affect the rate of water uptake by a plant?
when light intensity is increased, the stomata open wider to allow more carbon dioxide into the leaf for photosynthesis
how does air movement affect the rate of water uptake by a plant?
the movement of air removes water vapour, increasing the rate of diffusion of water vapour from the leaf
how does the temperature affect the rate of water uptake by a plant?
when temperature is increased, evaporation and diffusion are faster
what do plant hormones do?
control and coordinate plant growth and development
how do plant hormones control and coordinate plant growth?
the promote cell division and cause elongation in plants
what is the role of auxins in phototropisms and gravitropisms?
phototropisms - causes stem growth towards the light (shoots)
gravitropisms - causes growth towards the ground (roots)
what are some commercial uses of auxins in weed killers and rooting powders?
rooting powders - promote growth in the tips of shoots and roots, produce roots rapidly and start growing plants, enables growers to produce lots of clones of a good plant quickly
weed killers - they disrupt normal growth patterns while leaving grass and crops untouched
what are some commercial uses of gibberellins in germination, fruits and flower formation and the production of seedless fruit?
gibberellins in germination - ends seed dormancy, promote flowering, increase fruit size
fruits and flower formation - stem growth and flowering, can also reduce flower formation which can improve fruit quality
