Plants detect and respond to the daily cycle of light and darkness, and circadian rhythms People and animals are usually adapted for a daily cycle of light and dark. Given these facts, what do plants detect because of their circadian rhythm among the following options:
- Temperature changing
 - Life and death
 - heat produced
 - Soil and rocks
 - Light and dark
 - flow of electrons
 - Chemical energy
 - Rain and dryness


 

     Light and dark    