Plant hormones

• What is the role of auxins in plants?

  They control growth at shoot and root ends
• How do plants respond to stimuli compared to animals?

  Plants respond more slowly than animals
• How do plants maximize photosynthesis?

  By growing shoots towards light
• What do plants sense to grow their roots downwards?

  They sense gravity
• What do some plants sense to climb around objects?

  Touch
• How do plant hormones act compared to animal hormones?

  Plant hormones act locally, not systemically
• What are the two responses covered in the video?

  Phototropism and geotropism
• What is the effect of auxins on shoots?

  They stimulate growth in shoots
• What is the effect of auxins on roots?

  They inhibit growth in roots
• How do auxins behave in shaded areas of shoots?

  They accumulate on the shaded side
• What is the phototropic response of shoots?

  They are positively phototropic
• What is the geotropic response of shoots?

  They are negatively geotropic
• How does auxin accumulation affect shoot curvature towards light?

  Shaded side grows faster, causing curvature
• What happens to auxins in roots when exposed to light?

  They accumulate on the lower shaded side
• How do auxins affect root curvature in response to light?

  Upper side grows faster, causing downward curve
• What is the gravitropic response of roots?

  They are positively gravitropic
• How do auxins behave in roots when gravity is sensed?

  They accumulate on the lower side
• What is the effect of auxins on root growth when they accumulate?

  They inhibit growth on the lower side
• How does a root curve downwards when gravity is sensed?

  Upper side grows faster, causing downward curve
• What are the key rules regarding auxin accumulation in plants?

  • Auxins accumulate on shaded sides
  • Auxins accumulate on lower sides
• What are the differences in phototropic and gravitropic responses between shoots and roots?

  • Shoots:
  • Positively phototropic (towards light)
  • Negatively geotropic (away from gravity)
  • Roots:
  • Negatively phototropic (away from light)
  • Positively geotropic (towards gravity)
• What are the three plant hormones discussed in the video?

  Auxin, gibberellin, and ethylene
• What is the primary function of auxin in plants?

  It stimulates plant growth
• How can auxin be used in tissue culture?

  To stimulate growth of plant clones
• What happens when cuttings are treated with rooting powder containing auxin?

  They produce roots and grow into new plants
• How do auxins function as selective weed killers?

  They disrupt growth in broad-leaved plants
• What are the three main uses of gibberellin?

  Controlling dormancy, inducing flowering, growing larger fruit
• What is dormancy in seeds?

  Period before growth starts
• How does gibberellin help farmers with crop production?

  It induces germination out of season
• How does gibberellin affect flowering in plants?

  It can induce flowering on demand
• What is the effect of gibberellin on seedless fruit?

  It helps them grow larger fruits
• What is the primary use of ethylene in fruit?

  To stimulate the ripening of fruit
• Why is controlling the ripening process of fruit important?

  It allows for better transport and sale
• How do farmers use ethylene during fruit transport?

  To ripen fruit after transport
• How does ethylene work at the cellular level?

  It stimulates an enzyme for ripening
• What are the commercial uses of auxin, gibberellin, and ethylene in agriculture?

  • Auxin:
  • Stimulates growth
  • Used in tissue culture
  • Selective weed killer
  • Gibberellin:
  • Controls dormancy
  • Induces flowering
  • Grows larger fruit
  • Ethylene:
  • Stimulates fruit ripening
  • Controls ripening during transport