1) Gregor Mendel conducted research on pea plants and discovered the laws of inheritance including the law of independent assortment. 2) A monohybrid cross examines one trait, such as flower color in pea plants which can be purple or white. A cross between two plants with purple flowers could produce offspring with both purple and white flowers. 3) Sex-linked traits are genes found on the sex chromosomes. Examples of notation for traits like hemophilia are provided.