Principles of Classical Genetics

Principles of Classical Genetics


  • Classical Genetics is also referred to as Mendelian genetics, named after the monk and scientist Gregor Mendel.
  • Mendel’s experiments with pea plants formed the foundation for what we understand as the basic principles of genetics.

Mendel’s Laws

  • Mendel proposed three fundamental laws: the Law of Segregation, the Law of Independent Assortment, and the Law of Dominance.

Law of Segregation

  • The Law of Segregation states that pair of alleles separate during the production of gametes.
  • This ensures that each gamete contains only one allele from each pair.

Law of Independent Assortment

  • The Law of Independent Assortment explains that the alleles of two (or more) different genes get sorted into gametes independently of one another.
  • In other words, the allele a gamete receives for one gene does not influence the allele received for another gene.

Law of Dominance

  • The Law of Dominance asserts that one of the factors for a pair of inherited traits will be dominant and the other recessive, unless both factors are recessive.

Genotypes and Phenotypes

  • A genotype is the genetic makeup of an organism while a phenotype is the physical expression or characteristics of that genetic makeup.
  • For instance, having blue eyes (phenotype) can be due to having the genetic information that codes for blue eyes (genotype).

Role of Classical Genetics in Modern Genetics

  • Classical genetics provides a fundamental understanding from which more complex genetic processes are understood.
  • It forms the basis for studying DNA, molecular genetics, and genetic engineering.

Understanding classical genetics and Mendel’s laws will enable you to easily grasp more complex principles of modern genetics and DNA technology. It’s vital for understanding genetic variation, disease inheritance, and the science behind genetic modification.