Linkage and crossing-over of genes are alternatives of each other. Justify with the help of an example.

Explanation

Crossing over : The breaking during meiosis of one maternal and one paternal chromosome, the exchange of corresponding sections of DNA, and the rejoining of the chromosomes. This process can result in an exchange of alleles between chromosome.
Linkage in Fruit Files : It is the Proximity of two or more genes on a chromosome , the closer the ganes, the lower the probability that they will be separated during meiosis and hence the greater the probability that they will be inherited together.
An example of using linkage to explore gene position is provided by inheritance of eye color and baby color in fruit flies, both of which are located on the X chromosome. This example begins with purebred (homozygous) parents, one yellow-bodied and red-eyed, the other grey-bodied and white-eyed.
They mate to product all hetrozygous daughters, who carry the yellow-red combination on one homologous chromosome and the grey-white combination on the other. When the heterozygotes create gametes, the eye-color allles cannot assort independently from the body- color alleles because they are linked.