question: Why are a heteromorphic flower 's carpels and stamens different lengths ?
answer: so animal pollinators can not easily transfer pollen to the pistil
turker_answer: A heteromorphic flower 's carpels and stamens are different lengths so animal pollinators can not easily transfer pollen to the pistil .
rule-based: A heteromorphic flower 's carpels and stamens different lengths are because so animal pollinators can not easily transfer pollen to the pistil .