Module 1G Flashcards
What is the plant hormone called?
Auxin
Where is auxin produced?
In the tips of the roots and the shoots of the plant.
How does auxin actually work?
It diffuses backwards to stimulate the cell elongation process.
What does auxin promote?
Growth in the shoots.
What does auxin inhibit?
Growth in the roots.
What are shoots?
Positively phototropic, negatively geotropic.
What are roots?
Negatively phototropic, positively geotropic.
What happens when a shoot tip is exposed to light?
Auxin will accumulate on the shaded side. So the cells on the shaded side will grow and elongate and the curvature of the shoot will mean its bent towards the light.
What happens when a shoot is growing sideways?
Gravity will produce an unequal distribution of auxin, with a lot more present on the lower side of the shoot. This causes the shoot to bend upwards towards the light.
What happens when a root is exposed to light?
More auxin accumulates on the shaded side but because auxin inhibits growth in the roots they will start to bend back into the ground.
What happens when a root is growing sideways?
Gravity will cause an unequal distribution of auxin, with more on the lower side of the root. Because auxin inhibits growth in the root it will bend back down towards the ground.
How do selective weedkillers work?
Plant hormones are used that will only effect broad leaved weeds.
How does rooting powder work?
A cutting put in root powder that contains plant growth hormones will produce roots rapidly and start growing as a new plant.
How do you control the ripening of fruit?
Plant hormones are used to delay the ripening of fruit as it travels to the shop. Ripening hormones are then added as the product goes onto the shelves.
How do you control dormancy?
The plant hormone giberellin breaks dormancy and allows seeds to germinate.
