Heredity | Class 10 Science Notes

Mendel’s Experiments and Laws of Inheritance

Gregor Mendel, known as the father of genetics, conducted pioneering experiments on pea plants to uncover the principles of heredity. Mendel chose pea plants because they have distinct, easily observable traits such as flower colour (purple or white), seed shape (round or wrinkled), and seed colour (yellow or green). He performed controlled cross-breeding experiments by selecting pure-breeding plants—plants that always produce offspring with the same traits when self-pollinated. Mendel crossed plants with contrasting traits and observed the traits of their offspring over several generations. His experiments led to the formulation of two fundamental laws of inheritance: the Law of Segregation and the Law of Independent Assortment. The Law of Segregation states that each individual has two alleles for each trait, which segregate during gamete formation so that each gamete carries only one allele. The Law of Independent Assortment states that alleles of different genes assort independently of one another during gamete formation. Mendel's work was revolutionary because it introduced the concept of dominant and recessive traits, explaining why some traits appear in the first generation while others reappear in the second generation. His meticulous quantitative analysis provided a mathematical framework for inheritance.

📊 Diagram: (a); (b); Mendel was educated in a monastery and went on to study science and mathematics at the University of Vienna. Failure in the examinations for a teaching certificate did not suppress his zeal for scient

🧪 Activity: Mendel’s monohybrid cross experiment with pea plants to observe dominant and recessive traits.

🔗 Connection: This section leads to the detailed explanation of inheritance patterns over generations, using Mendel’s experimental results.