Mammoth Memory

Auxin (pronounced Ox Inn)

Auxin is a hormone that controls growth by stimulating or restricting growth in plant cells. Auxin in shoots stimulates growth but has the opposite effect in roots.

Auxin in shoots stimulate growth but has the opposite effect in roots

Auxin - Stimulates in the Shoots and

               Restricts in the Roots

The start letters S and R help you remember which is which.


Auxin (pronounced Ox Inn) – Growth hormone

Mnemonic to remember Auxin is a growth hormone

The Ox ingested (auxin) too much growth hormone.


In a shoot

The shaded side contains more auxin and grows longer, causing the shoot to bend towards the light.

 Auxin has the effect of elongating the plant in relation to the suns position, the auxin moves to one side

In a root

If a root is placed horizontally, the bottom contains more auxin than the top side. This makes the bottom side of the root grow less than the top side, causing the root to bend in the direction of gravity. This is the opposite of auxin in the shoot.

Auxin causes root cells to elongate less but makes the roots bend down towards nutrients

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