The scientist who discovered some basic rules about inheritance is Gregor Mendel. He is often called the "father of modern genetics" for his groundbreaking work with pea plants.

Mendel's experiments in the mid-19th century led him to formulate three fundamental laws of inheritance:

1. The Law of Segregation: Each inherited trait is determined by two alleles (alternate forms of a gene), one from each parent. These alleles separate during gamete formation (meiosis), so each gamete only receives one allele.

2. The Law of Independent Assortment: Different traits are inherited independently of each other, meaning the inheritance of one trait does not affect the inheritance of another.

3. The Law of Dominance: Some alleles are dominant, meaning they mask the expression of the recessive allele. If an individual has one dominant allele and one recessive allele, the dominant trait will be expressed.

Although Mendel's work was initially overlooked, it was rediscovered in the early 20th century and laid the foundation for our understanding of genetics.