Similar to humans and animals, plants have hormones which are small, naturally occurring molecules that contribute to a variety of physiological processes, such as development and defense. 

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​Some examples of how plant hormones contribute to various processes:​

• Fruit ripening

  • Ethylene, a gaseous plant hormone, is involved in fruit ripening. For example, if green unripe bananas are placed into a plastic bag for a few days they will ripen more quickly because ethylene is being produced.

• Leaf senescence

  • When leaves lose their iconic green color and fall in autumn months this is because of the plant hormones auxin, ethylene, and cytokinin.  

• Phototropism

  • Auxin, the growth plant hormone, is involved with the orientation of towards light. Often throughout the day plants will move towards the light and change their orientation.

  • Ethylene is associated with flower buds opening in the morning.

• Medicine

  • A derivative of the plant hormone, salicylic acid, is the main ingredient in the commonly used pain-reliever aspirin.​

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