Plants detect and respond to the daily cycle of light and darkness, and diurnal cycles Diurnal cycles are the daily cycles of light and darkness. Given these facts, plants detect and respond to what among the following options:
- water cycles
 - Greenhouse gasses
 - plant cycles
 - Electrical energy
 - sleep cycles
 - heat or cold
 - Diurnal cycles
 - Temperature changing


 

       Diurnal cycles  