 In organisms that use chromosomal crossover to exchange DNA and recombine genes , errors in alignment during meiosis can also cause mutations . Errors in crossover are especially likely when similar sequences cause partner chromosomes to adopt a mistaken alignment ; this makes some regions in genomes more prone to mutating in this way . These errors create large structural changes in DNA sequence – duplications , inversions , deletions of entire regions – or the accidental exchange of whole parts of sequences between different chromosomes ( chromosomal translocation ) . 
