1. PLANT GROWTH & DEVELOPMENT

2. I. Germination - the process by which a plant embryo resumes its growth
*a seed contains a plant embryo that is in a
state of suspended animation
*a seed cannot sprout until water and
oxygen penetrate the seed coat
*many seed coats must be damaged before
they can sprout
ex: exposure to fire
passing through a digestive tract
falling down rocks

3. *seeds sprout in response to certain
changes in the environment
ex: increase temperature
increase soil moisture
exposure to light

4. Seed Germination Shoot – grows toward light
Root – grows toward gravity

5. II. Life Spans
perennials – a plant that lives for several years; many reproduce many times during their life span, while others reproduce only once before they die
annuals – a plant that completes its life cycle and then dies within one growing season
biennial - a flowering plant that takes two growing seasons to complete its life cycle

6. Perennials
(Many Seasons)
Annuals
(One Season)
Biennials
(Two Seasons)

7. Meristems – regions of active cell division
1. primary growth – growth that increases the length or height of a plant
ex: apical meristems – the tips of stems & roots
2. secondary growth – growth that increases the width of stems and roots
ex: cork cambium – lies within the bark and
produces cork
vascular cambium – lies under bark &
produces vascular tissue

8. Regulating Growth & Development
Plant needs: CO2, water
14 minerals
Hormones: chemicals that regulate plant
growth and development
ex: auxin – stimulates growth causing
shoot to elongate

9. How Auxin Affects Growth

10. Minerals Needed by Plants:

11. Responses: 1. tropism is a response to a stimulus
*phototropism – response to light
*gravitropism – response to gravity
*thigmotropism – response to touch
*hydrotropism – response to water
Fig 6 p. 582
2. positive tropisms – move toward a
stimulus
negative tropisms – move away from a

12. 3. photoperiodism – response of a plant to
the length of days and nights
( seasonal patterns)
4. dormancy – the condition in which a plant or a seed remains inactive

13. Tropisms: hydrotropism – external stimulus to water
Phototropism – external stimulus to light
Gravitropism –external stimulus to gravity
Thigmotropism -internal stimulus to hormones

14. Venus Fly Trap :
Nastic Movement – a non-directional response to stimulus ex: response to the external stimulus of pressure from an insect