Complex sentence: In meiosis the enzyme is SPO11, which is related to DNA topoisomerases, which change DNA by transiently breaking one or both strands, passing the unbroken DNA strand or strands through the break and repairing the break.
Split into simpler sentences: In meiosis the enzyme is SPO11, which is related to DNA topoisomerases. These enzymes change DNA by transiently breaking one or both strands, passing the unbroken DNA strand or strands through the break and repairing the break.