Final answer:
The feature not characteristic of a multifactorial trait is 100% concordance in identical twins, as multifactorial or polygenic traits show variability influenced by both genetic and environmental factors. Therefore correct option is D
Step-by-step explanation:
The feature that is not a characteristic of a multifactorial trait is 'd. 100% concordant in identical twins.' Multifactorial or polygenic traits are controlled by many genes and demonstrate a wide range of phenotypes due to the influence of multiple alleles. The expression of these traits can also be significantly influenced by the environment, leading to variability even among identical twins. Traits like height, skin color, and weight are typical examples of polygenic traits.
Unlike monogenic traits, which are controlled by a single gene, polygenic traits can be affected by epistasis, where the effect of one gene is modified by another. Consequently, identical twins, even though they share the same genes, may not display a trait exactly the same way if the expression of those genes is influenced by environmental factors.