Matric Notes Class IX Biology Role of Water

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Water

Water makes approximately 70% of the body tissues. It is an essential component of the protoplasm. One can live without food for more than a week but a person can die within two to three days due to lack of water.

Importance of Water

1. It plays an important role in digestion.
2. It helps in transport of digested food and other materials in dissolved form.
3. All the chemical reactions inside the cell take place in the presence of water.
4. It helps in excretion of urine, removal of faeces.
5. Enzymes become more active in solution form.
6. It keeps the blood thin and so that it can be easily circulated.
7. Water regulates the body temperature.
8. Its deficiency in tbe body causes dehydration, which can prove fatal.
9. Plants cannot photosynthesize without water.
10. The people living in hot and dry places need more water. By breathing, sweating and urination about 2-3 liters of water is lost per day