Plants, like all living organisms need water to survive. Since most plants consist of 95% water, taking in enough water is essential for plant growth and development.
The main way in which plants take in water (and nutrients) is through osmosis by their roots. Osmosis is the movement of water through a semi permeable membrane, allowing small molecules through along with the water. If you’ve ever dug up a plant, you’ll notice that plants send out many long root strands, with many having smaller root hairs along the sides. All these roots and root hairs increase the surface area for the plants to take in enough nutrients and water. That’s why root development is critical to a young plant’s growth. The stronger the root system, the more water and nutrients it can take in, and the larger it can grow.
Once water has entered into the roots, it moves through the stems and into the leaves and tissues again using the principle of osmosis. Once in the leaves, water in the plant tissue will be released into the air through transpiration. When plants do not get enough water, the pressure within each plant cell drop/collapse, and you mean see visible signs of the plant starting to wilt. Thus, plants need to continually take in water through their roots in order to grow and develop.
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