Study the below given statements and choose the correct statements with respect to linkage and recombination ?

i) Morgan carried out several dihybrid crosses in Drosophila to study genes that were sex-linked.

ii) Linkage is the phenomenon, where two or more genes are located on the same chromosome and their recombination frequency in a test cross progeny is less than 50%.

iii) All the genes present on one chromosome form a linkage group and its number in organism is equal to haploid number of chromosomes.

iv) When two pairs of traits are combined in a hybrid, segregation of one pair of characters is always independent of the other pair of characters.

v) In Drosophila genes for white eyes and yellow body were very tightly linked and showed only 1.3 percent recombination.

vi) In Drosophila genes for white eyes and miniature wing showed 37.2 percent recombination.