| A | B | 
| Tropism | The directional response plants make to a stimulus | 
| Geotropism | Response to gravity | 
| Phototropism | Response to light | 
| Negative | Response away from a stimulus | 
| Positive | Response towards a stimulus | 
| Water and minerals | Found by plant roots when they grow down | 
| Light | Found by plant shoots when they grow up, out of the soil | 
| Undergound | Where developing seedlings are when they can't use light as a stimulus | 
| Shaded side | Where plants produce most auxin | 
| Grow faster | What auxin makes cells on the shaded side do | 
| Bend | What the shoot does if cells on one side grow faster than those on the other | 
| Shoot tip | Where auxins are produced in a plant | 
| Diffuse | How auxins move from the tip to the shaded side of a shoot | 
| Photosynthesis | Why do plant shoots need to grow towards the light | 
| Rooting powder | What promotes plant cuttings to grow roots | 
| Pollination | What hasn't happened in plants tricked by sprayed hormones into producing seedless fruits | 
| Big leaves | The reason weeds take in so much hormone that they grow too fast and die | 
| Weedkiller | You spray it on lawns and its full of plant growth hormones | 
| Grass | A plant with small leaves that doesn't take up much hormone when you spray your lawn | 
| Growth and development | Regulated by plant growth substances |