Question

Distance between two linked genes is measured in map units that depict:

• A. Ratio of crossing over between them
• B. Crossover value
• C. Number of genes between them
• D. Both b & c

Answer 1

The correct option is B

Crossover value

Based on experiments on Drosophila, Morgan suggested that the frequency of crossing over between two genes would depend on the physical distance between them. Alfred Sturtevant used the frequency of recombination, also known as crossover value between gene pairs on the same chromosome as a measure of the distance between genes and ‘mapped’ their position on the chromosome (genetic maps).