Course Content
UPSC Notes Samples
Full Syllabus Covered | 100% as per Official UPSC Syllabus
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1. Art & Culture Sample
Covered under topic 1. Indian culture will cover the salient aspects of Art Forms, Literature and Architecture from ancient to modern times.
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1. Indian culture will cover the salient aspects of Art Forms, Literature and Architecture from ancient to modern times. (copy)
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2. Modern Indian history from about the middle of the eighteenth century until the present- significant events, personalities, issues. (copy)
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5. History of the world will include events from the 18th century such as Industrial revolution, World wars, Redrawal of national boundaries, Colonization, Decolonization, Political philosophies like Communism, Capitalism, Socialism etc.- their forms and effect on the society.
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7. Role of women and women’s organizations, Population and associated issues, Poverty and developmental issues, Urbanization, their problems and their remedies.
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10.2. Introduction to Maps
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GS2
All topics that need updates are given below.
2. Functions and responsibilities of the Union and the States, issues and challenges pertaining to the federal structure, devolution of powers and finances up to local levels and challenges therein.
All topics that need updates are given below.
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5. Parliament and State Legislatures – structure, functioning, conduct of business, powers & privileges and issues arising out of these.
All topics that need updates are given below.
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6. Structure, organization and functioning of the Executive and the Judiciary; Ministries and Departments of the Government; pressure groups and formal/informal associations and their role in the Polity.
All topics that need updates are given below.
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12. Welfare schemes for Vulnerable Sections of the Population by the Centre and States and the Performance of these schemes; Mechanisms, Laws, Institutions and Bodies constituted for the Protection and Betterment of these Vulnerable Sections.
All topics that need updates are given below.
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GS3
All topics that need updates are given below.
11. Science and Technology- developments and their applications and effects in everyday life.
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GS3: BIODIVERSITY AND ENVIRONMENT
All topics that need updates are given below.
1. Environment
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GS4
All topics that need updates are given below.
GS3: SCIENCE AND TECHNOLOGY
All topics given below
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1. Motion & Measurements
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9. Metals & Non-Metals
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10. Energy
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12. Plant Organisms
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14. Life Processes
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18. Biotechnology
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19. Information Technology
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20. Space Technology
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National & International Current Affairs (CA) 2025
Current affairs of all months are given below
delete UPSC Sample Notes [English]

i.3. How does the intricate web of food chains influence the dynamics of the environment?

Intricate threads of ecosystem Food Chains

  • A food chain refers to the order of events in an ecosystem, where one living organism eats another organism, and later that organism is consumed by another larger organism. 

Web of Life in Ecosystem Food Chains

  • Organisms depend on the producers for their nourishment. 
    • The organisms, whether consuming food directly from producers or indirectly by preying on other consumers, are referred to as consumers. 
    • Various organisms at different biotic levels come together to form a food chain.

Trophic Levels and Consumer Relationships

  • Each level within the food chain is termed a trophic level. 
    • Autotrophs: The initial trophic level consists of autotrophs or producers, responsible for harnessing solar energy and making it accessible for heterotrophs, or consumers. 
    • Primary and Secondary Consumers: Herbivores, or primary consumers, occupy the second trophic level, while smaller carnivores, or secondary consumers, are found at the third level. 
    • Tertiary Consumers: Larger carnivores, or tertiary consumers, constitute the fourth trophic level.

Food Chain formation

  • The Flow of Nutrients and Energy from one organism to another at different trophic levels forms a food chain.

 Grass→ insects→ frog→ snake →eagle

Interconnected Chain and Ecosystem stability:

  • Forests contain numerous interconnected food chains, and these chains are interdependent. 
    • Every aspect of the forest relies on other components. 
    • Disrupting one food chain has repercussions on others within the ecosystem.

Unidirectional Energy Flow and Trophic Level Losses:

  • Interactions among environmental components involve the transfer of energy from one part of the system to another. 
    • This energy flow is unidirectional.
    • In terrestrial ecosystems, green plants capture approximately 1% of the sunlight’s energy falling on their leaves and convert it into food energy.
    • As energy progresses through trophic levels, it steadily diminishes due to losses at each level. 
    • Much energy is dissipated as heat to the environment, some is expended on digestion and work, and the remainder goes towards growth and reproduction.

10% Rule  and Trophic Level Dynamics:

  • Typically, only 10% of the food an organism consumes is transformed into its own body mass and becomes available for the subsequent level of consumers in the food chain. 
    • Because so little energy is available for the next level of consumers, food chains usually consist of just three or four steps. 
    • The substantial energy loss at each step means that very little usable energy remains after four trophic levels.
  • At the lower trophic levels of an ecosystem, there are generally more individuals, with the largest population being the producers.

Food Webs in Ecosystem

  • Food webs exhibit significant variations in terms of length and complexity. 
    • Instead of a linear food chain, each organism is typically consumed by multiple other species, which, in turn, are prey for several other organisms. 
    • This complex relationship is often depicted as a network of branching lines rather than a straight line food chain.