Mendel law of independent assortment does not hold true for the genes ...
As per linkage experiments carried out by Morgan, the two linked genes do not always segregate independently of each other and F2 ratio deviated very significantly from 9:3:3:1 ratio (expected when two genes are independent). Hence, if linkage was known at the time of Mendel, he would riot have been able to explain law of independent assortment.
Mendel law of independent assortment does not hold true for the genes ...
Explanation:
Mendel's law of independent assortment states that the inheritance of one trait does not affect the inheritance of another trait. This is only true for genes that are located on different chromosomes or are far apart on the same chromosome. However, Mendel's law of independent assortment does not hold true for genes that are located closely on the same chromosome.
Reasons why Mendel's law of independent assortment does not hold true for genes that are located closely on the same chromosome:
1. Linkage: Genes that are located closely on the same chromosome tend to be inherited together because they are physically linked and do not assort independently. This is known as linkage.
2. Crossing over: Although genes that are located on the same chromosome tend to be inherited together, crossing over during meiosis can cause them to assort independently. However, the frequency of crossing over is inversely proportional to the distance between the genes. Genes that are close together are less likely to undergo crossing over and are more likely to be inherited together.
3. Genetic recombination: Genetic recombination is the process by which new combinations of genes are formed during meiosis. Genes that are located closely on the same chromosome are less likely to undergo genetic recombination and are more likely to be inherited together.
Conclusion:
Therefore, Mendel's law of independent assortment does not hold true for genes that are located closely on the same chromosome because of linkage, crossing over, and genetic recombination.