1. 9.3 Growth in Plants

2. Plant hormones: Respond to changes in the environment Regulate growth
Regulate reproduction and flowering
Regulate water loss
Regulate growth by controlling mitosis and cell division

3. Meristem Tissue
Undifferentiated tissues that become many different types of tissues
Located where plants exhibit major growth

4. 2 types of Meristems Apical Meristems Lateral Meristems
Located at the top and the root of plants
Allows for growth of new leaves and flowers
Allows roots to grow down into the soil
Lateral Meristems
Responsible for secondary growth in woody plants
Allows them to increase stem and root thickness

5. Mitosis and Cell Division
Occur in the shoot apex
Provide cells needed for extension of the stem at that location
Also important for development of leaves.

7. Micropropogation of plants
The practice of rapidly multiplying stock plant material to produce a large number of plants, using modern plant tissue culture methods.
Uses tissue from shoot apex, nutrient agar gels and growth hormones
Used in plants to increase population faster than seeding time would allow

8. Tropisms
A directional movement in plants in response to a stimulus

9. Type of Tropism
Response
Phototropism
Response to light
Gravitropism
Response to gravity
Thigmotropism
Response to touch
Thermotropism
Response to temperature
Chemotropism
Response to substance
Hydrotropism
Response to water

10. Auxin (plant hormone) Responsible for phototropism
Affects cells on the dark side of the plant
causes the cells to elongate
When light shines directly down on a plant shoot auxin is equally distributed this causes the plant to grow straight

11. Auxin
Auxin efflux pumps can set up concentration gradients of auxin in plant tissue.
Auxin influences cell growth by changing the pattern of gene expression.