In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

Q: Question: Formic acid is found in the secretions of? Answer: stinging ants

A: Formic acid is found in the secretions of stinging ants.
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Q: Question: Which model can be used to trace genetic inheritance? Answer: pedigree chart

A: The pedigree chart model can be used to trace genetic inheritance.
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Q: Question: What is caused by differences in density at the top and bottom of the ocean? Answer: deep currents

A:
Deep currents are caused by differences in density at the top and bottom of the ocean.
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