Question

On analysis of the alignment scores of random sequences will reveal that the scores follow a different distribution than the normal distribution called the _________

(a) Gumbel equal value distribution

(b) Gumbel extreme value distribution

(c) Gumbel end value distribution

(d) Gumbel distribution

This question was addressed to me in an online interview.

Origin of the question is Assessing the Significance of Sequence Alignments in chapter Sequence Alignment of Bioinformatics

Answer 1

Correct choice is (b) Gumbel extreme value distribution

The best explanation: Originally, the significance of sequence alignment scores was evaluated on the basis of the assumption that alignment scores followed a normal statistical distribution. If sequences are randomly generated in a computer by a Monte Carlo or sequence shuffling method, as in generating a sequence by picking marbles representing four bases or 20 amino acids out of a bag, the distribution may look normal at first glance. But on further analysis the above result was obtained.