According to Journal of Biological Chemistry 158, human brain and heart are composed of ________water?
Correct answer: C. 73%
- A. 75%
- B. 81%
- C. 73%
- D. 89%
Explanation
The commonly cited composition for the human brain and heart is about 73% water, so option c matches the stated reference. The other percentages are values sometimes quoted for different tissues or sources, not the figure intended here. Students may choose 75% because it is a familiar rounded estimate for water-rich tissues.
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