Polygenic Inheritance

Polygenic inheritance is governed by multiple genes, not multiple alleles of a single gene. In polygenic inheritance, the effects of each allele are additive, contributing to the phenotype. Therefore, Statement I is incorrect, and Statement II is correct.

Polygenic traits are controlled by multiple genes, usually located on different chromosomes. These traits do not follow the simple Mendelian inheritance pattern but instead show continuous variation and are often influenced by environmental factors as well. Such traits exhibit a non-mendelian inheritance pattern. For example, traits like skin color, height, and weight in humans are polygenic traits and are influenced by multiple genes with varying degrees of dominance and interaction. Thus, the correct answer is Non-mendelian inheritance pattern.