2.70 describe the geotropic responses of roots and stems

2.70 •roots: •they are positively geotropic 

                   •a root growing sideways will also have more auxin on it’s lower side 

                             •in a root, the extra auxin inhibits growth so root bends downwards as the top cells grow more  

         •stems: •they are negatively geotropic 

                      •they grow away from gravity in order maximise sunlight 

                                •when they grow sideways, gravity makes the auxin distribution uneven, so more auxin is used on the lower side

                                          •the lower side to grow faster, bending the shoot upwards