* 07/16/96 Plant Growth 26-2 Unlike animals plants continue to grow and increase in size throughout their lives. Prep Needed: Set up LT Side Three 11/22/2018 *
Guide For Reading What are meristems? What is a tropism? What do auxins do for plant growth? What changes must occur as a plant grows? 11/22/2018
Meristematic Regions Apical meristems Root meristems Cambiums vascular cambium cork cambium Flowers, leaves grow also from meristematic tissue. 11/22/2018
Tropisms Plants grow in response to cues from their environments. These responses are called tropisms. (Frame 25668 - LT Side Three) 11/22/2018
Geotropism Reponse to gravity Stems grow away (negative) Roots grow toward (positive) - (Chapter 18 - LT Side Three) 11/22/2018
Phototropism Response to light Stems are positively phototropic Roots are negatively phototropic 11/22/2018
Thigmotropism Response to touch Sensitive plant Briar leguminosae 11/22/2018
Plant Hormones Auxins Cytokinins Gibbeillins Ethylene 11/22/2018
Auxins Produced by the apical meristem Apical dominance Auxin produces phototropism 11/22/2018
Auxins Apical dominance Stronger Weaker 11/22/2018
Cytokinins Like auxins cytokinins effect the rates of plant growth and cell division. 11/22/2018
Gibberillins Gibberillins regulate the rate which cells elongate. 11/22/2018
Ethylene Ethylene promotes fruit ripening (Frame 25296 - LT Side Three) 11/22/2018