Question

Consider this sequence A—O—B —C—D—E—F, be a DNA sequence where O is the centromere. Which of the following will be a pericentric inversion?

(a) A—O—B—D—E—F

(b) B—O—A—D—E—F

(c) D—B—O—A—E—F

(d) A—O—E—D—B—F

I have been asked this question in my homework.

This intriguing question comes from Chromosomal Abnormality : Inversion topic in division Chromosomal Basis of Inheritance of Cytogenetics

Answer 1

Right choice is (d) A—O—E—D—B—F

Easy explanation: Pericentric inversion is the inversion that doesn’t involve the centromere. Here in option A there is no change at all, option B and C are including the centromere. Only option D doesn’t involve the centromere in the inverted sequence, so it is pericentric.