UPSC Study Material of Environment for IAS Prelims Exam: Target PT 2021 (Quick Revision Notes) The UPSC CSE Prelims is a tough and demanding exam that requires aspirants to answer 100 multiple choice questions which call for IAS aspirants to study a wide range of topics with conceptual clarity. Environment and Ecology forms a very important part of the exam and is the base for many dynamic questions too. Every year, about 20-25 of 100 questions asked are related to Environment and Geography, thus making it a very crucial subject for the preparation of the UPSC IAS examination. What do the IAS aspirants need? IAS aspirants need a single-source material that is a complete guide for their preparation in the UPSC CSE Prelims examination. This source is brought to them by GS SCORE to aid them to achieve success in this very attempt. The material covers all important and relevant facts and material required to be studied by aspirants in a single booklet. This helps to ease their preparation and provides consolidated and complete UPSC notes.