Practice question

F2 generation of monohybrid cross Tt by Tt arises from fusion of two gamete types per parent. Four fertilization combinations produce TT once, Tt twice counting both reciprocal fusions, and tt once. Distinguishable genotypic proportions are therefore 1 TT to 2 Tt to 1 tt, genotypic ratio 1:2:1. Phenotypic ratio under dominant expression collapses to 3:1, 1:1 describes test cross, 9:3:3:1 dihybrid, accurate genotypic array reflects equal segregation of alleles and random union maintaining Mendelian expectations. This principle is routinely tested in NEET, CBSE 11-12, CUET, CSIR-NET, GATE and MSc Genetics examinations requiring clear conceptual distinction.