If progeny plants inherited a single whole gene set from each parent, then the experiment in Fig. 9.5 cannot work. This is because the two characteristics ‘R’ and ‘y’ would then be linked to each other and cannot be independently inherited....

These are the lines on Pg 145 ncert heredity and evolution
and fig 9.5 is the experiment related to independent inheritance of two seperate traits.

Please explain the above passage

Dear student,

According to Mendel's law of Independent Assortment, when two pairs of a trait are combined in a hybrid then one pair of character segregates independent of other pair of character, i.e., the alleles of one gene sort into the gametes independently of the alleles of another gene.Thus, the traits are inherited independently.

This could be further explained as follows :
A gene have two alternate forms , which are known as alleles, out of which one is dominant and one is recessive, These two alleles of a same gene refers one set of genes.
  • If the progeny inherits a single whole gene set from each parent , for example :YY (yellow) and  yy (green) and then the experiment will fail,as the progeny will be YYyy ,which is not possible. Thus progeny receives only one allele either Y or y of a gene from each parent. 
  • Mendel gave law of independent assortment according to which traits (seed colour and seed shape in this case) separate independently. If a progeny inherits complete whole set of gene from parent that means trait of shape and colour will be inherited together and then these characters R (seed shape) and Y (seed colour) will be linked and Mendel's law will fail (Genetic linkage could be defined as the tendency of alleles that are located close together on a chromosome to be inherited together) . Now we know that progeny never receives whole gene set and thus traits are not linked. 
I hope this will clear your doubt!


  • 15
That is explained by one of Mendel's laws ,
Google about Mendel's laws of inherirence
  • -5
I Know that, The Law of independent assortment which says that each trait is expressed independent of each other. But i am confusing about how R and y can be linked together if progeny plant takes a single whole gene set. Anyone?
  • 6
What are you looking for?