Question

Linkage is an exception of which of the Mendel's laws?

• A. Law of segregation
• B. Law of independent assortment
• C. Law of dominance
• D. None of the above

Answer 1

Answer: (B)

Law of independent assortment

Mendel's law of independent assortment is applied only to those genes which are located on separate chromosomes because the linked genes of a linkage group (chromosome) inherited together. A dihybrid contains either linked genes or independently assorted genes, can be determined by test crossing it with a double recessive parent.

The genes from both parents do not influence each other but still they remain together up to the point of formation of zygote. Only one chromosome's trait goes to the child but both chromosomes remain together.

The third Mendelian law states that hereditary factors are inherited independently. This statement holds true for all seven features analyzed by Mendel. His correspondence with C. V. Nageli nevertheless mentions briefly the fact that this law is sometimes broken. Such an example was found by W. Bateson, E. R. Saunders and R. C. Punnet when they studied the sweet pea Lathyrus odoratus in 1905. They examined the inheritance of the flower colour and the pollen structure. 381 F${}_2$-plants were analyzed.