14.2 - Plant Hormones Flashcards
What plant growth factors are The stimuli that trigger plant responses The role of IAA in phototropism and gravitropism How IAA controls growth by elongation
What are plant growth factors?
Chemicals influencing plant development
How do plant hormones differ from animal hormones?
Plant hormones act locally
What external stimuli trigger plant responses?
Light
What is phototropism?
Growth towards or away from light
What is gravitropism?
Growth towards or away from gravity
What is hydrotropism?
Growth towards or away from moisture
What is the role of IAA in tropisms?
Stimulate or inhibit cell elongation
Where is IAA synthesised?
Growing tips of shoots and roots
How does IAA affect shoots?
Stimulates cell elongation
How does IAA affect roots?
Inhibits cell elongation
How does IAA control positive phototropism in shoots?
Moves to shaded side
How does IAA control negative phototropism and positive gravitropism in roots?
Moves to lower shaded side
How does IAA cause shoot elongation?
Binds to cell membrane
