Biology Plant Hormones

plants also have hormones.hormones make sure plants grow in useful direction(e.g.towards light)
Auxin
1. plant growth hormone
2. controls growth near tips of shoot&roots.
3. controls growth of plant in reponse to light(phototropism),gravity(geotropism)moisture
4. produced in tips&moves backwards to stimulate cell elongation process-occurs in cells just behind tips.
5. if tip of shoot removed-no auxin avaliable so shoot may stop growing
6. extra auxin promotes growth in shoot but inhibits growth in roots
1.shoot grows towards light-when shoot tip exposed to light more auxin accumulates on side in shade than side in light-makes cells grow faster on shaded side son shoot bends towards light
2.shoot grows away from gravity-when shoot grows sideways,gravity produces an unequal amount of auxin in tip,with more auxin on lower side,causes lower side grow faster bending root upwards
3.roots grow towards gravity-root growing sideways have more auxin on lowerside.in root extra auin inhibits growth.means cells on top grow faster&roots bend downwards
4.roots grow towards moisture-uneven amount moisture either side of root produces more auxin on side with more moisture.inhibits growth on that side causing root to bend towards moisture
plant hormones have uses in agriculture& can be extracted&used by people,or artificial versions can be made.most weeds in crop fields are broadleaved unlike grasses&cereals-have narrow leaves. selective weedkillers-made of plant growth hormones-only affect broaded leaved plants. distrupt normal growth pattern,soon kills leaves crops untouched.
plant cuttings wont always grow in soil. if add rooting powder-contains auxin,they'll produce roots rapidly&new plants grow.helps growers produce lots of clones of a really good plant quickly

Next up

Biology Plant Hormones

Description

Resource summary

Similar

	Created by georgia_x_barnes over 10 years ago