SB6f- Plant hormones

• What do plant hormones do?

  Control and coordinate plant growth and development, and allows plants to respond to changes
• What is tropism?

  A plant’s response to a stimulus by growing. A positive tropism is when a plant grows towards the stimulus.
• What is phototropism?

  Process of growing towards light
• What is gravitropism?

  Process of growing towards gravity
• Plants showing positive phototropism

  Plant shoots show positive phototropism because they grow towards the light, and show negative gravitropism
• Auxins with phototropism

  1. Auxins are produced at the very tip of the shoot and move down the shoot
  2. As auxins move downwards, they move towards the shaded parts of the shoot
  3. The auxins cause cell elongation
• How do plants show positive gravitropism?

  Plant root show positive gravitropism because they grow downwards, towards the pull of gravity, and also show negative phototropism
• Auxins with gravitropism

  1. Auxins inhibit growth in the roots
  2. Auxins are pulled downwards by gravity and inhibit cell elongation in the roots, causing the roots to grow downwards, causing it to increase cell elongation in shoots causing it to grow upwards
• What are auxins?

  Plant hormones that control the rate of cell elongation
• What are gibberellins?

  Plant hormones that also control cell elongation but can also influence germination
• What is ethene?

  A gas that controls ripening
• Cells in SHOOTS grow MORE

  Cells in ROOTS grow LESS