Question

The following table gives cross-over values (COVs) of genes T, U, V and W on a chromosome:
$\begin{array}{cc}\text{Linked gene pair}& \text{COV}\\ \text{T and U}& \text{25}\\ \text{T and V}& \text{5}\\ \text{V and U}& \text{30}\\ \text{U and W}& \text{10}\\ \text{V and W}& \text{20}\end{array}$
Which of the following represents the correct order of arrangement of the genes on the chromosome?
(correct answer + 2, wrong answer - 0.50)

• A. V, T, W, U
• B. T, W, U, V
• C. T, V, W, U
• D. V, W, T, U

Answer 1

The correct option is A V, T, W, U

Cross over values depicts frequency of recombination or crossover frequency. The likelihood of a crossover happening is proportional to the physical distance between the genes. A crossover or recombination frequency of 1% is equal to 1 map unit. A map unit is the measure of distance between two gene loci. Maximum possible recombination frequency is 50%. Hence,