When normal and mutant alleles are present on opposite chromosomes of a homologous pair,the heterozygotes are called as:

What is the result of linkage and crossing over?

Two heterozygous parents are crossed. If the two loci are linked,what would be the distribution of phenotypic features in the $F_{2}$ generation for a dihybrid cross?

Which of the following represents the frequency of recombination between two genes that are inversely proportional to the strength of linkage?

The linkage map of a fruit fly has a total map distance of $66$ units. The gene for yellow body $(a)$ is at one end and the gene for short hair $(y)$ is at the other end. What will be the recombination frequency between these two genes $(a$ and $y)$?

The coupling and repulsion theory was proposed by: