Answer:
Crossing over is responsible for genetic variation of an organism.
Explanation:
Crossing over between two homologous chromosomes of non-sister chromatids is responsible for the genetic variation in an organism because in crossing over the segments of one chromatids are exchanged with one another which is different from one another. Due to difference in the segments of two chromatids, the difference occurs in the genetic makeup as well as in the physical structure and appearance of that organisms.
