plant hormones

What is auxin

A plant hormone that controls growth by affecting cell elongation.

Where is auxin produced?

In the tips of shoots and roots.

What is phototropism?

Growth in response to light.

What is gravitropism

Growth in response to gravity

How does auxin cause shoots to bend towards light?

Auxin moves to the shaded side and stimulates cell elongation there

How does auxin affect roots?

It inhibits cell elongation, causing roots to grow downwards.

Which tropisms do shoots show?

Positive phototropism and negative gravitropism.

Which tropisms do roots show?

Negative phototropism and positive gravitropism.

Why do selective weedkillers kill broad-leaved plants?

They cause uncontrolled growth due to high auxin levels.

Give two uses of auxins in agriculture.

Rooting powder and selective weedkillers.

What key phrase do examiners look for with auxins?

“Unequal distribution of auxin causes unequal cell elongation.”

What does auxin do in roots

Inhibits growth