Is it smarter to focus on NCERT Biology line-by-line or use thick reference books for NEET?

For NEET Biology, NCERT (Class 11 and 12) is the single most important source, and you should know it almost line by line because a large share of questions are lifted directly from NCERT statements, diagrams and even the in-text boxes. Read it multiple times, highlight factual lines, and pay attention to tables, examples and figure captions that students usually skip. Reference books help only for extra practice MCQs and for clearing a concept you found hard in NCERT, not as a replacement. A good rhythm is: master NCERT first, then test yourself with previous years' NEET questions topic-wise, and return to NCERT every time you make a mistake. Depth in NCERT beats breadth across many books for Biology.