Reading Intermediate 🏆 For a certificate exam 🗺️ TOEFL Junior

How Pine Cones Protect and Disperse Seeds

This short scientific passage explains how pine cones open and close in response to air moisture to safeguard and release their seeds.

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Pine cones have a clever natural way to keep their seeds safe. Inside each cone, tiny seeds develop until they are mature enough to grow on their own. The outer part acts as a protective cover against cold temperatures and hungry animals. Most remarkably, pine cones react to moisture in the air. When the air becomes wet, the scales absorb water, which causes them to swell and close tightly. This mechanism keeps the seeds completely dry. Conversely, when the air is dry, the scales shrink and bend backward. This opening movement allows the wind to disperse the seeds to new places where they can sprout.