Father of Genetics:
Gregor Johann Mendel is considered the “Father of Genetics.” He was an Austrian monk who conducted experiments on pea plants (Pisum sativum) between 1856 and 1863. Through his systematic study of inheritance patterns, he laid the foundation of modern genetics.
Mendel’s Law of Segregation (Law of Purity of Gametes):
Mendel’s Law of Segregation states that the two alleles of a gene separate from each other during gamete formation, so that each gamete receives only one allele of a particular trait.
Explanation:
Consider a monohybrid cross between tall (TT) and dwarf (tt) pea plants.
• The tall plant has two dominant alleles (TT).
• The dwarf plant has two recessive alleles (tt).
When crossed, the F₁ generation produces all tall plants (Tt), because the dominant allele (T) masks the effect of the recessive allele (t).
During gamete formation in the F₁ generation (Tt), the two alleles separate or segregate from each other. As a result, two types of gametes are formed: one carrying T and the other carrying t.
When these gametes combine in the F₂ generation, the ratio obtained is:
Genotypic ratio: 1 TT : 2 Tt : 1 tt
Phenotypic ratio: 3 Tall : 1 Dwarf
This shows that the alleles remain pure and separate during gamete formation, which proves the Law of Segregation.
Thus, Mendel’s Law of Segregation explains how traits are inherited from parents to offspring through the separation of allele pairs during reproduction.