Question

The particulate theory of inheritance was demonstrated by Mendel’s pea plant experiments, but does this always occur? Do you believe it is possible for a trait to be both polygenic and multifactorial?

Answer 1

The particulate theory of inheritance as demonstrated by the experiments of Mendel on the pea plant state that alleles undergo segregation during gametogenesis and again reunite during fertilization and assort independently of each other, thus, giving a dominant or recessive effect. These experiments and postulates were based upon the assumption and observation that an allele is either completely dominant or completely recessive in nature.

However, practical observations have stated that there are some deviations from Mendel's pattern of inheritance which do not follow these postulates. For example, the traits following polygenic inheritance do not follow these postulates. Unlike the normal assumptions, the polygenic inheritance is based upon the fact the quantitative phenotype is based upon the number of alleles present in the individual.

Similarly, there are other deviations from Mendel's patterns such as incomplete dominance and co-dominance. These patterns of inheritances too do not follow the normal particulate theory.

Hence, although the Mendel's postulates are extremely helpful and enlightening to understand the principles of genetics, many evidences do suggest deviations from these postulates.