Which scientist is known for their contribution to the principles of heredity?

The correct choice, Mendel, is renowned for establishing the foundational principles of heredity through his experiments with pea plants in the mid-19th century. Mendel's systematic approach to studying the inheritance of traits led to the formulation of what are now known as Mendel's laws of inheritance, which include the law of segregation and the law of independent assortment. His work laid the groundwork for modern genetics, demonstrating how traits are passed from one generation to the next and establishing the concept of dominant and recessive alleles.

In contrast, Darwin was pivotal for his theory of evolution and natural selection but did not specifically focus on the mechanisms of heredity. Watson and Crick are recognized for their discovery of the structure of DNA, which is critical for understanding heredity, but they built upon Mendel's earlier findings. Their work contributed to a later understanding of how genetic information is transmitted but did not originate the principles of heredity itself.