Mendel’s Law

Mendel’s Law

Mendel’s Law

Mendel’s Law

Mendel’s have proposed three law on the basic of his experiment which are listed and explained below:-

  1. Law of Dominance
    It states that “When a cross is made between two pure contrasting characters, only one of them is able to express phenotypically while the other remains hidden in F1 generation”. The character which can express itself is dominant and other one is recessive.
  2. Law of Segregation or Law of Purity Of Gametes
    It states that “During the formation of gametes, alleles for particular character separates; they do not intermix with each other”. Hence gamete is always pure.

    For example: A monohybrid cross between pure tall and pure dwarf plant results hybrid tall as F1 generation. It consist of Genotype ‘T t’.

    Mendel's Law of Segregation

When a F1 hybrid were allowed for selfing …

Mandel's Law of Segregation
Phenotype ratio – 3:1
Genotype ratio – 1:2:1
One pure tall plant, two hybrid plant and one pure dwarf plant was observed. This results explain that during the formation of gamete of F1 generation, two types of gametes were formed without intermixing. One gamete receive the alleles from Tall(T) and one gamete receive the alleles from dwarf(t) which means each gamete is pure for particular character and they segregates during gametes formation.



  1. Law of Independent Assortment
    It states that ” The inheritance of one particular character to next generation is independent of inheritance of another character i.e they assort random and freely.
    Eg. When a hybrid crossed is performed between Tall and Round Seeded Plant with Dwarf and Wrinkled Seeded Plant. All F1 generation were found to be round and yellow seeded.

    Mendels law of independent assortment
But in F2 generation ,after Selfing…..

mendels law of independent assortment
Phenotype ratio: 9:3:3:1
Genotype ratio: 1:2:2:4:1:2:1:2:1
Four different phenotype and nine different genotype was obtained. The four different phenotype were possible due to random assortment of particular character. Beside the yellow and round seeded plant green and round seeded plant was also obtained. This means that round seeded character assort independently with yellow character as well as dwarf character.In the same way beside wrinkled and green seeded plant , wrinkled and yellow seeded plant was also obtained which means that green character is not associated with wrinkled character and can assort independently.


#law of independent assortment#law of purity of gametes#law of segregation#