photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.
Cacti grow in the desert, which is a very hot climate. Not the best for both gaining and maintaining water supplies, due to the fact that water becomes vapour very quickly in conditions such as a desert (unless we're talking about polar deserts).
Keeping their stomata closed during the day stops water vapour from escaping their cells. While this does inhibit growth and stop new water molecules from entering, it allows the cactus to maintain a healthy amount of water within itself.
Doppler effect and redshift as the light coming from stars from the distance can be shifted in the same way as a pitch of sound does
The requirement was established principally to address the growth of LISTERIA MONOCYTOGENES, which is a bacteria that has the capacity to continue growing even at refrigerated temperatures. The date marking procedure was put in place in order to make sure that the affected foods are discarded before the bacteria can initiate food borne illness.