After finally being able to finally understand Mendel’s experiment and his techniques (if you didn’t you can read my article on Genetic Basis of Inheritance click here and this will redirect you to my article) when it comes to laws it is a headache to understand each and so much pain to remember it so to make it easy for you I have prepared a table of difference between Mendel’s first and second law of inheritance.
Difference between Mendel’s first law and second law:
|Mendel’s first law||Mendel’s second law|
|1. Mendel’s first law states that a single trait can exist in different forms or alleles||1. Mendel’s second law states that the alleles of two different genes does not depend upon each other but instead they are independently sorted into gametes|
|2. This law is also known as law of segregation||2. This law is also known as the law of independent assortment|
|3. This law is based on monohybrid cross experiment||3. This law is based on dihybrid cross experiment|
|4. The ratio of the offspring produced will be 3:1||4. The ratios of the offspring produced will be 9:3:3:1|
What are the three laws of Mendel ?
Mendel’s first law:
Mendel’s second law:
This law is universally applicable because all sexually reproducing organisms are diploid (2n) meaning they have two sets of chromosomes and the gametes are haploid (n) meaning having only one set of chromosome. Since this most of the organisms produce sexually this law is applicable universally.
Mendel’s third law:
Mendel also performed trihybrid cross ratio but since it is not mentioned in your syllabus we won’t be going in detail. After he performed trihybrid cross he came to a conclusion that there is indeed random fusion taking place and each gamete will receive only one allele from each pair of traits and they are independent to go anywhere and enter into any gamete they want. They do not tend to carry their parental combinations and are totally independent hence this is known as the law of independent assortment.