Chapter 16. Management of Natural Resources

Management of Forest Resources * Forest resources include the land, trees and different life forms including bacteria, fungi, ferns, flowering plants, nematodes, insects, birds, reptiles and large animals. * Forests are biodiversity hotspots – together, all the species of plants and animals help maintain the ecological stability of the forests. * We depend on the ... Read more

Chapter 15. Our Environment

Our Environment * All the interacting organisms in an area together with the non-living constituents of the environment form an ecosystem. * Organisms in the ecosystem are classified into three groups – Producers, Consumers and Decomposers. * Organisms that make their food from inorganic substances are known as producers. * Organisms that consume the food ... Read more

Chapter 14. Sources of Energy

Sources of Energy * A non-renewable source of energy is one that cannot be replenished in a short period of time. Non-renewable fuels are classified as:    * Fossil fuels like coal, oil and natural gas    * Nuclear fuels like uranium, tritium and thorium * A renewable source of energy is one that can ... Read more

Chapter 13. Magnetic Effects of Electric Current

Magnetic Effects of Electric Current * When an electric current passes through a conductor, a magnetic field is created around the conductor. This phenomenon is known as the magnetic effect of electricity. * A magnetic field is the extent of space surrounding a magnet where the magnet’s effect can be felt. * Magnetic field lines ... Read more

Chapter 12. Electricity

Current Electricity Basics * Electric current is uniform flow of charges in a particular direction. * The rate of flow of charge or uniform motion of electrons: ( I = Q/t) * Potential difference is the work done in moving a unit charge between two points in an electric field against the direction of force: ... Read more

Chapter 11. Human Eye and Colourful World

Human Eye * The human eye is an optical device that serves as our organ of sight. It transforms light waves reflected from objects we see into images. The major parts of the human eye and their functions are:    *  Sclera: Protects and contains internal parts    *  Cornea: Refracts incident light    *  ... Read more

Chapter 9. Heredity and Evolution

Heredity and Variations * The process of passing of the traits from parents to offspring is called Heredity. * Offspring are never an exact copy of their parents. They show minor differences, which are called Variations. * Mendel was the pioneer among Geneticists who found the inheritance of characters from parents to offspring. * A ... Read more