4.5.4.1 control and coordination

• Why do plants produce hormones?

  to coordinate and control growth and responses to light and gravity
• what are plant responses to light called?

  phototropism

  
  
• what do unequal distributions of auxin cause?

  unequal growth rates in plant roots and shoots
• what are plant shoots in terms of tropisms?

  positively phototropic and negatively geotropic
• what are roots in terms if tropisms?

  negatively phototrophic and positively geotropic
• what is hydrotropism?

  the movement of roots towards water
• how do auxins affect plant shoots?

  they cause cell elongation

  
  
• how do auxins affect plant roots?

  they inhibit growth
• where are auxins made?

  in the tip of the shoots and roots
• what do gibberellins do?

  initiate seed germination, end dormancy, flowering and larger fruit
• what does ethene control?

  cell division and ripening of fruits