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Creation Day 4 God reveals His "heavenly clocks" in the night and day sky The next time you see beautiful flowers blooming in the spring , you will know how God perfectly programmed the timing behind each blossoming plant .
After the first day of spring (March 21st), as the daylight hours grow longer and air temperatures in the Northern Hemisphere get warmer, God programmed all dormant winter plants to begin releas ing a hormone named auxin inside of the ir barren stem s. Auxin caus es the dormant (sleeping) cells to begin growing again directing the stem 's tip upward toward the sun light, a plant movement known scientifically as phototropism.
During the spring and summer months, the leaves of both trees and flowering plants get their green color from a chemical pigment found inside the cells of each leaf called chlorophyll A. Chlorophyll A helps plants capture sunlight to drive the process called photosynthesis, which is how plants release Earth's oxygen supply to the air and also produce glucose , the food needed for the survival of both plants and animals.
Tree leaves also have orange and yellow pigments. These pigments are called carotenoids, which are also responsible for the color in pumpkins and carrots. When temperatures and daylight hours begin to drop in the fall, chlorophyll production also declines, and these other colors - yellows, oranges , reds, purples and browns - are revealed. As light levels and temperatures continue to drop, the flow of auxin to the leaves slows and levels of another plant hormone, ethene, rises. Increased ethene levels signals the base of the leaf to die. The dead leaf turns brown and falls to the ground.
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