Question

Total number of transition and transversion that can take place in genome is___________

(a) 2 and 6

(b) 6 and 4

(c) 4 and 6

(d) 4 and 8

I had been asked this question in an internship interview.

This interesting question is from DNA Mutation in portion DNA Mutation, DNA Repair, Transposable Elements of Cytogenetics

Answer 1

Right answer is (d) 4 and 8

For explanation I would say: Transition is the replacement of a purine by another purine or a pyrimidine by another pyrimidine. Transversion is the replacement of a purine by a pyrimidine, or a pyrimidine by a purine. So there are 4 possible transition A—G and C— T, and 8 possible transversions A—C, A—T, G—C, G—T.