Sex-linked inheritance was discovered by

When two genes are situated very close to each other on a chromosome:

Two genes '$a$' and '$b$' show $20\%$ recombination. What will be the proportion of gametes produced by a dihybrid $F_1$ individual with the genotype $++/ab$,derived from a cross between $++/++$ and $ab/ab$?

Genes on the same chromosome can be:

When is the Law of Independent Assortment not applicable to genes?

The distance between two linked genes on a chromosome is measured in cross-over units,which is: