PLANT HORMONES

• What is geotropism?

  Growth towards or away from the gravitational pull
• What is phototropism?

  Growth towards or away from a light source
• Facts about auxins

  • produced in tips of shoots and roots
  • Diffuse to the cells behind the tips
  • Unequal distribution of auxins cause unequal growth rates in the plant roots/shoots
  • Auxins promote cell elongation in the shoots
  • Auxins inhibit root growth in the roots
  • They are used as a selective weedkiller
• What do gibberellins do?

  • initiate seed germination
  • encourages flowering and fruit growth
• What does ethene do?

  Gas is released by plants which controlls cell diffusion and fruit ripening