The principal components of the plasma membrane are lipids (phospholipids and cholesterol), proteins, and carbohydrates. The plasma membrane protects intracellular components from the extracellular environment. The plasma membrane mediates cellular processes by regulating the materials that enter and exit the cell.
Members of the Shudra caste, for example, are relegated to performing hard physical work regardless of their skill, intelligence, or ambition. Those born into the Brahman caste must attend university or become a member of the clergy, even though they may show no interest or aptitude toward that end.
The caste system in India is a system of social stratification which has pre-modern origins, was transformed by the British Raj, and is today the basis of reservation in India. It consists of two different concepts, varna and jÄti, which may be regarded as different levels of analysis of this system.melser and Lipset propose in their review of Hutton's study of caste system in colonial India the theory that individual mobility across caste lines may have been minimal in British India because it was ritualistic.