GS I is very advantageous to the candidates with background of geography as good theoretical understanding of physical geography of world and india can help you directly or indirectly to answer at least 25 questions.Those who are not from geography background,focus on the following topics

-platetectonics:concept and tectonic events such as mountain building,earthquakes,volcanic activity-concept of geomagnetism and seafloor spreading ,seismic waves and internal structure of the earth-structure and composition of atmosphere ,heat budget -temperate and tropical cyclones:characteristics and differences

-el nino ,la nina and monsoon and jetstreams(three types such as tropical easterly,subtropical westerly and polar frontal jet streams)-precipitation:especially types -bottom topography of ocean basins:a generalized view-ocean currents-patterns of salinity and temperature of oceans-coral reefs and coral bleaching

-physical setting of India,drainage pattern of himalayan and peninsular rivers,northeast monsoon,western disturbance-genesis and distribution of soils,soil horizons and profile-Major biomes and characteristics

-Biodiversity:terrestrial and marine,levels of biodiversity:genetic,species and ecosystems and respective significance and threats to biodiversity,CBD,Biodiversity and traditional knowledge,conflict between CBD and TRIPS,National Biodiversity Act's provisions,threatened,vulnerable and endangered species,differences between National Park,Sanctuary,Bio Reserve,Biogeographic zones,wetlands in india and Ramsar provisions-all pollutants of air,water and land:their sources,hazardous elements and sources ,conceptual understanding of soil degradation and desertification,major treaties and summits on environment.

-Climate change:natural factors versus anthropogenic factors,latest stays of UNNFCC and all aspects related to four contentious issues:Mitigation,Adaptation,Finance and Technology transfer.Green technologies and associated issues like cost-effectiveness and awareness etc.CDM and Carbon trading,various issues related to carbon sequestering .Search widely on internet.

-Biotechnology:GM organism and associated issues like genetic contamination,loss of biodiversity,allergy,emergence of super pest etc,stem cell and latest breakthrough,importance of bioinformatics,gene therapy,DNA fingerprinting etc.-Carbon nanotube,nanotech in medicine,agriculture and electronics:just have an overall idea

-Indian space program me and three stage nuclear programme:just read INDIA year book-for government dev programs and inclusive issues ,compile from various govt sites including pub and INDIA year book.

-a very important area is conceptual understanding of monetary policy of RBI and related concepts like repo,reveres repo,bank rate,CRR etc;fiscal policy and related concepts like fiscal deficit,revenue deficit,primary deficit,twin deficits,finance and related issues like FII,FDI,participatory notes and controversies,rupee appreciation and depreciation and their implications and causative factors,current account and capital account convertibility etc.(Read NCERT public income accounting and search specific concepts and issues on net)

-Be acquainted with all issues of financial inclusion like ,MFI regulation,micro insurance etc.-Poverty: various criteria by different committees.Poverty and SHG etc.-History:give most importance to freedom movement and read only one standard book like bipan chandra.-current events questions are very few.You can manage it well.

-For polity,read either Laxmikant or DD Basu.My suggestion would be to read DD Basu.Local governance:read ARC reports.-Rights issue:focus on various human rights treaties and provisions,rights based acts and provisions

In GS -I you can answer many questions by making very intelligent guess based on your overall understanding.As the factual questions are extinct now,try to have conceptual understanding of every issue and idea.If you can't answer more than 50 questions comfortably,try to take some risks by making BLIND guess too!You will not get whisky if you don't take risk!!