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Biology IX | Health and Diseases | Part 1
Health and Diseases | Part 1 Human Diseases Definition : Disease may be defined as a disorder in the physical, physiological, psychological or social state of a person caused either due to nutritional deficiency, hormonal disorder, genetic disorder, pathogen or any other reason. Types of Diseases Diseases are broadly grouped into two categories : a.…
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Science IX | Natural Resources: Our Environment | Part 3
Natural Resources: Our Environment | Part 3 Soil Soil is the portion of the earth’s surface consisting of disintegrated rock and decaying organic material. It provides the support for many plants and animals. Thickness of soil on the earth’s surface ranges from a few millimeters to 3-4 meters. Terrestrial plants depend for their nutrients, water…