In this case, the statement of Mendelian segregation law stating that every allele will segregate independently during gamete formation is not applied. It occurs because there are some genes in one chromosome that do not segregate during gamete formation. The genes are said to be linked, so it is called gene linkage.
Gene linkage occurs in the genes that lie in the same chromosome with locus which is close to each other. The situation causes the frequency of each gamete is not similar. Recombinant frequency will be smaller so that the genotype and phenotype frequency in F2 is different from Mendel's ratio' look at the following example!
If heterozygous yellow smooth seed corn (CcSs) is crossed with white wrinkled corn (ccss), the phenotypic ratio of the offsprings does not follow mendelian law pattern. Most of the offsprings have parental type, whereas the recombinant type does not appear. Parental type offsprings are the new offsprings that have similar phenotype to the parents', while recombinant type offsprings are the new offsprings that have different phenotype from their parents.
The Possible Cross Result Between Heterozygous Yellow Smooth Corn (CcSs) and white Wrinkled corn (ccss)