Genetic Inheritance: Mendel's Law of Segregation

What observation led Mendel to propose the Law of Segregation?

In Mendel's monohybrid crosses, why did the recessive phenotype re-appear unaltered in the F2 generation?

Answer:

Mendel's observation of the re-appearance of the recessive phenotype in the F2 generation of his monohybrid crosses led him to propose the Law of Segregation.

Gregor Mendel, often referred to as the father of modern genetics, conducted experiments with pea plants in the 19th century to study the inheritance of traits. One of his key observations was the consistent re-appearance of the recessive phenotype in the F2 generation of his monohybrid crosses. This phenomenon puzzled Mendel and prompted him to propose the Law of Segregation.

The Law of Segregation states that pairs of alleles for a trait separate during gamete formation, with each gamete receiving only one allele. This process explains why the recessive phenotype can re-appear in later generations, even if it is not expressed in the F1 generation. The segregation of alleles occurs randomly, ensuring that each allele has an equal chance of being transmitted to the offspring.

Mendel's groundbreaking work laid the foundation for our understanding of genetic inheritance and provided insights into the mechanisms of heredity. His experiments with pea plants revolutionized the field of genetics and established the fundamental principles of genetic inheritance.