In his work on pea plants, Mendel found that plant height was inherited independently of the type or color of the seed coat. This finding changed the concept and laid the foundation on inheritance which was previously thought as a blend of genes from parents. From Mendel’s experiment, it was clear that heredity is a result of distinct units of inheritance called genes — displayed as traits with each trait coming from one parent. A trait comes in pairs (two genes) and each form or variant is called alleles. A pair of trait could be identical (homozygous) or different (heterozygous). However, as research advances, we now knew that genes doesn’t only come in pairs but could be more. Modern genetics say that traits actually are controlled by multiple genes including environmental factors.