Unit 7--Plants

1
Unit 7--Plants

• Chapter 25
• Plant Responses Adaptations

2
Plant Hormones

• Auxin first discovered
• located in growing tips of roots/stems
• for stem elongation
• inhibits bud growth
• leaf fruit drop

3
Plant Hormones

• Ethylene for fruit ripening drop or leaf
  flower drop

4
Place fruits in a brown bag to trap ethylene gas
release to speed up ripening
5
Plant Hormones

• Gibberellins for seed germination, fruit
  development stem elongation

6
Tropisms

• Growth response toward a stimulus
• Phototropism toward light
• Ex sunflower

7
Tropisms

• Gravitropism (or geotropism)
• toward earths center
• Ex roots (positive) stems (negative)

8
Tropisms

• Thigmotropism
• toward a support or something touched
• Ex tendrils on a climbing vine

9
Modified Leaves

• Cactus spines
• Tendrils
• Carnivorous plants

10
Specialized Plants

• Parasitic plants
• Ex mistletoe
• Epiphytes
• Ex orchids, ball moss

11
Classification by life span

• Annuals
• entire life cycle in one growing season
  
• Ex tomato plant

12
Classification by life span

• Biennials
• lives through two growing seasons,
  separated by dormancy
• Ex cabbage carrot

13
(No Transcript)
14
Classification by life span

• Perennials
• live many years and through many
  periods of dormancy
• Ex trees, shrubs
• Also, bluebonnets