Principles of Inheritance and Variation

Classical genetics - one of the most heavily weighted and problem-rich chapters in NEET (typically 4-6 questions/year across Botany and Zoology). It covers Mendel's experiments on the garden pea and his laws of dominance, segregation and independent assortment (mono- and dihybrid crosses, the test cross, and 3:1 and 9:3:3:1 ratios); the deviations from Mendelism - incomplete dominance, co-dominance and multiple alleles (ABO blood groups), pleiotropy and polygenic inheritance; the chromosomal theory of inheritance and Morgan's work on linkage and recombination; sex determination (XX-XY, XX-XO and ZZ-ZW); mutation; and the Mendelian and chromosomal genetic disorders (haemophilia, colour blindness, sickle-cell anaemia, thalassaemia, phenylketonuria; Down's, Klinefelter's and Turner's syndromes) with pedigree analysis. Six graded practice sets - two Easy, two Medium, one Hard and one NEET previous-year set - each opening with comprehensive NCERT-anchored notes covering 100% of the current syllabus, followed by single-correct MCQs with full explanations.