Practice question

Monohybrid self-cross Tt by Tt generates two gamete types per parent T and t. Combining in Punnett square produces four possible fertilisation events representing total genotype combinations regardless of identity, namely T fertilised by T, T by t, t by T and t by t. Two middle events share genotype Tt, resulting in distinguishable genotypes three but combinations four. Count two reflects allele number, three distinct genotypes, eight would require three segregating genes, accurate total possible zygotic combinations four underlies 1:2:1 genotypic ratio. This principle is routinely tested in NEET, CBSE 11-12, CUET, CSIR-NET, GATE