1. 25-1 Hormones and Plant Growth Ch. 25 Plant and Responses and Adaptations

2. Hormone Substance produced in one part of an organism that affects another part of the same organism

3. Target Cell Cell that has a receptor for a particular hormone

4. Phototropism Tendency of plants to grow toward a source of light

5. Auxin Substance produced in the tip of a seedling that stimulates cell elongation

6. Gravitropism Response of a plant to the force of gravity

7. Lateral Bud Meristematicarea on the side of a stem that gives rise to side branches

8. Apical Dominance Phenomenon in which the closer a bud is to the stem’s tip, the more its growth is inhibited

9. Herbicide Compound that is toxic to plants

10. Cytokinin Plant hormone produced in growing roots and in developing fruits and seeds

11. Gibberellin Growth-promoting substance produced by plants

12. Ethylene Plant hormone that stimulates fruits to ripen

13. Key Concept Plant hormones are chemical substances that control a plant’s patterns of growth and development, and the plant’s responses to environmental conditions.

14. Key Concepts Auxins are produced in the apical meristem and are transported downward into the rest of the plant. They stimulate cell elongation.

15. Key Concepts In plants, cytokinins stimulate cell division and the growth of lateral buds, and cause dormant seeds to sprout.

16. Key Concepts Gibberellins produce dramatic increases in size, particularly in stems and fruit.

17. Key Concepts In response to auxins, fruit tissues release small amounts of the hormone ethylene. Ethylene then stimulates fruits to ripen.