Control in plants / Plant hormones

Plants sensitive to light, moisture and gravity.

Shoots grow : Towards light, against force of gravity.

Roots grow: Towards moisture, direction of force of gravity.

Produce hormones to coordinate + control growth.

Auxin (hormone) coordiantes and controls growth in plants. Unequal distribution of hormones causes unequal growth rates.

Used in Agriculture.

- Chemicals synthesised that are similar to plant hormones

- People concerned chemicals entering food chain could be toxic

Weed Killlers

Chemicals used specific to weed e.g dandilion

- Cause weed to grow quickly

- Weed cannot sustain rate of growth

- Dies.