Question

If the genes order in bacteria is His gal met. Which of the following genes have the least probability of getting incorporated alone?

(a) All have equal probability

(b) Met

(c) Gal

(d) His

This question was addressed to me in a job interview.

I'd like to ask this question from Gene Mapping in Bacteria by Transformation topic in chapter Genomics : The Mapping and Sequencing of Genomes of Cytogenetics

Answer 1

Right choice is (c) Gal

To explain: Gal can be incorporated alone only by the event of double cross over. Double crossover at such short stretch is of least occurrence so the probability of it being incorporated alone is least.