Plant hormones

• What is the process called when plant shoots grow towards light?

  Phototropism
• What do scientists believe controls phototropism in plants?

  Plant hormones
• What is the name of the hormone produced at the tips of shoots?

  Auxin
• What happens to shoots when their tips are removed?

  They do not grow towards the light
• What effect does covering the tips of shoots with foil have?

  They do not grow towards the light
• What does covering the lower parts of shoots with foil indicate?

  Lower parts are not sensitive to light
• How do auxins help shoots grow towards light?

  • Auxins produced at the tip
  • Concentrate on the darker side
  • Cells on darker side grow faster
  • Causes shoot to bend towards light
• What is the term for plant roots growing towards gravity?

  Gravitropism
• How do auxins behave in roots under gravity?

  They inhibit cell growth on the lower side
• What are the roles of gibberellins and ethylene in plants?

  • Gibberellins: Start seed germination
  • Ethylene: Controls cell division and fruit ripening
• What should higher-tier students know about plant hormones?

  Gibberellins and ethylene roles
• Why is it important to learn about plant hormones for exams?

  They are frequently tested topics