Question

For palindromic sequences, what is the structure of the dot plot?

(a) 2 intersecting diagonal lines at the midpoint

(b) One diagonal

(c) Two parallel diagonals

(d) No diagonal

I have been asked this question in an online interview.

This question is from Dot Matrix Sequence Comparison in portion Sequence Alignment of Bioinformatics

Answer 1

Right option is (a) 2 intersecting diagonal lines at the midpoint

To elaborate: For perfectly aligned sequences there is a diagonal formation of dot plot. For palindromic sequences i. e. for sequences that are symmetrical from the midpoint of the sequence, there exist 2 intersecting diagonals on the plot.