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.
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Question: Question: What do muscles need to contract? Answer: stimulus

Answer: Muscles need stimulus to contract.


Question: Question: What normal bodily occurrence can cause skeletal muscles to involuntarily contract? Answer: reflexes

Answer: Reflexes normal bodily occurrence can cause skeletal muscles to involuntarily contract.


Question: Question: What part of the sperm contains the genetic material? Answer: the "head"

Answer:
The "head" of the sperm contains the genetic material.