Practice question

Quantitative traits like human height, milk yield or grain weight show continuous phenotypic spectra rather than distinct classes, produced by polygenic inheritance where many genes each exert small additive effect combined with environmental variance. Distribution approximates normal curve, heritability estimated statistically via QTL mapping. Monogenic discontinuous pattern characterises qualitative traits. File lists loss of chromosome as option C, which actually describes aneuploidy, not typical architecture of quantitative variation, correct biological mechanism therefore involves multiple loci with cumulative dosage and environmental modulation. Cytological correlation with prophase pairing, metaphase alignment and anaphase separation provides visual anchor for memorising genetic laws.