Sex linkage was first observed by.....

Drosophila has four pairs of chromosomes. How many linkage groups does it have?

As the length of the chromosome increases in an organism,which of the following increases?

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 $ab/ab$?

The greater the length of the chromosomes in an organism, the greater the genetic variation. This variation is obtained from which of the following processes?

The arrangement of genes on chromosomes is