Mendel's Laws of Inheritance - PhysicsTeacher.in

In this post, we will discuss Mendel’s Laws of Inheritance. The laws are known as Law of Dominance, Law of segregation of genes or Law of purity of gametes, and Law of independent assortment.

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Mendel's Laws of Inheritance – 3 laws of inheritance

Mendel’s Laws of Inheritance – 3 laws of inheritance

Here, we will discuss 3 laws of Inheritance:
(1) Law of Dominance
(2) Law of segregation of genes or Law of purity of gametes
(3) Law of independent assortment

Law of Dominance

Law of Dominance: When two contrasting alleles are brought together the dominant allele masks the effect of the recessive allele. That means, only the dominant allele expresses its phenotype. Example: Allele for tallness is dominant over allele for dwarfism in pea plant.

In F1 generation (heterozygous condition), the dominant allele expresses itself masking the recessive allele.

Law of segregation of genes or Law of purity of gametes

Law of segregation of genes or Law of purity of gametes: When two contrasting alleles are brought together in F1 generation, then they remain together in the heterozygous condition without blending but the two alleles again separate or segregate at the time of gametogenesis (during the development of the gamete in meiosis process) in such a way that each gamete consists of just one allele for that gene.

During the process of meiosis, when gametes are formed, the allele pairs segregate, i.e. they separate. Example: Monohybrid cross for the flower color in pea plants.

Law of independent assortment

Law of independent assortment: When two pairs of independent alleles are brought together simultaneously (dihybrid cross), then each pair of alleles passes from the parents to the offspring without depending on the other pair of alleles.

This law is valid for those traits that are not related to each other such as seed color and seed shape of pea plant. When two independent characteristics are passed from parents to offsprings, those characteristics are assorted independently during the production of gamete. This indicates that the inheritance of one character will not influence the inheritance of the other.