Mendelian genetics refers to the principles of inheritance proposed by Gregor Mendel in the 19th century. Mendel's experiments with pea plants led to the discovery of basic rules of inheritance, such as the segregation and independent assortment of genes. These principles form the foundation of modern genetics and provide a framework for understanding how traits are passed down from parents to offspring. Mendelian genetics also includes concepts such as dominant and recessive alleles, genotype and phenotype, and Punnett squares for predicting the outcomes of genetic crosses.