Given a scientific question, generate a correct answer to it.

Input: Consider Input: What happens when turgid cells in a nonwoody tissue push against each other?

Output: the tissue stiffens

Input: Consider Input: What can radioactive strontium replace in the human body making it dangerous?

Output: calcium

Input: Consider Input: Although much of the heart's basic structure is complete by the end of the fifth week, what fetal structures remain until birth or shortly after?
Output: blood shunts