{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

lecture+6--post - Outline Lecture 6 Hormones and responses...

Info icon This preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Outline Lecture 6: Hormones and responses to environment • Hormones – Definition – Discovery and effects • Auxin • Cytokinin • Gibberellin • Abscisic acid • Ethylene New hormones? Responses to environmental cues – Light – Gravity – Mechanical stimuli
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 Fig. 15-9, p. 243 auxin in block replaces tip growth resumes auxin transported down into agar block tip removed growth stops auxin source on one side growth on one side curvature proportional to auxin concentration Auxin discovery involved these steps: 1) The shoot tip is necessary for growth 2) There’s an actual physical substance being made in the shoot tip that can be transferred to an agar, and thence back to the plant 3) That substance definitely causes growth, because if differentially distributed, growth favors the side exposed more to the substance in question. 4) Voila! Auxin was discovered!
Image of page 2