1. Plants 8.5 Plant Growth and Tropisms

2. POINT > Describe 3 types of tropisms POINT > Identify 2 important plant hormones POINT > Define dormancy POINT > Describe 3 types of plant life-cycles

3. A tropism is a plant’s response to a stimulus Three types of plant tropisms: 1. Phototropism: most plants respond to light http://plantsinmotion.bio.indiana.edu/plantmotion/movements/tropism/phototropism/corn/cornworship.html POINT > Describe 3 types of tropisms

4. 2. Gravitropism: most plants respond to gravity Leaves and stems grow away from gravity Roots grow toward gravity POINT > Describe 3 types of tropisms

5. 3. Thigmotropism: some plants respond to touch Ivy and grape vines are examples of plants that do this POINT > Describe 3 types of tropisms

6. What is a tropism? What is phototropism? What is thigmotropism? What is gravitropism? CHECK:

7. Tropisms are controlled by plant hormones: chemicals that control plant growth Auxin is a hormone that controls phototropism POINT > Identify 2 important plant hormones

8. Auxin causes the cells away from light to elongate This makes the plant bend toward the light POINT > Identify 2 important plant hormones

9. Gibberellin is a hormone that controls germination, flowering, fruit development and dormancy We manipulate gibberellins to produce fruits without seeds POINT > Identify 2 important plant hormones

10. What are hormones? What are two things that are controlled by gibberellins? What plant hormone makes plants grow toward light? CHECKPOINT >

11. Many plants go into dormancy during the winter Dormancy is a period of no growth or activity When days get short and temperatures get colder plant hormones (gibberellins) cause the plant to stop growing POINT > Define dormancy

12. Angiosperms have 3 types of life cycles 1. Annual plants live for only one year POINT > Describe 3 types of plant life-cycles

13. Angiosperms have 3 types of life cycles 2. Biennial plants live for two years and flower only in the second year POINT > Describe 3 types of plant life-cycles

14. Angiosperms have 3 types of life cycles 3. Perennial plants can live for many years and flower every year. Most perennials have a woody stem POINT > Describe 3 types of plant life-cycles

15. How long do biennial plants live? How long do perennial plants live? How long do annual plants live? CHECKPOINT >

16. Read pages 284-287 S.A. #1-3 page 287 GRAS pages 118-121 Homework