Experts solve this fast

Mendelian dihybrid cross is represented as follows:



The ratio for the dihybrid cross according to Mendelian experiments on peas is 9:3:3:1. The obtained no. of seeds in the above experiment is in accordance with this ratio.

Number of Round yellow seeds= 9 x 64=576 (or around 630)
Number of Round green seeds= 3 x 64= 192 (or around 216)
Number of wrinkled yellow seeds= 3 x 64= 192 (or around 202)
Number of wrinkled green seeds= 1 x 64= 52

Mechanism of inheritance: 
Law of independent assortment- According to this law, When two pair of traits are combined in a hybrid, one pair of character segregates independently of the other pair of character.

For example- In a cross involving one pea plant producing round, yellow seeds and the other producing wrinkled green pods,  then it is not necessary that offspring will have same combination. 

Hope this clears your doubt.
Regards.