Auxins - a hormone found in plants that stimulate growth in plants

Auxins as weed killers - by spraying auxin onto the leaves of a plant, it can trigger rapid, uncontrolled growth, killing them

Phototropism - a plants response to light

Geotropism - a plants response to gravity

Auxins response to uneven light - auxin moves to the unlit side of the shoot, the cells respond by growing more so the shoot bends due to weight, towards the light.

Auxin and even light distribution - auxin will also have an even distribution, so the shoot grows evenly

Auxin in the root - auxin gathers on the lower side, the root grows more on the side with least auxin, making it bend due to gravity and grow downwards, after it has grown down, the auxin becomes evenly spread

Auxin in the shoot - auxin gathers on the lower side, the shoot grows more on the side with most auxin, so it bends and grows up away from the force of gravity, when it has grown up the auxin becomes evenly spread again.

Gibberellins - a plant hormone that is important in initiating seed germination

Different ways to use gibberellins:

• used in the brewing industry, to speed up germination of barley seeds to make malt

• Used to promote flowering throughout the year

• To increase the size of fruit, (spray to replace natural hormone so they grow well)

Using ethene - used to control ripening of fruit, this is useful since firm fruit is easier to transport, when fruit arrives it can be added to the atmosphere (at warm temp) and rapidly ripened to the perfect stage when needed.