[Campbell Biology P.78] Based on the information provided, which of the following statement... | Practice Question

Based on the information provided, which of the following statements about elements in the human body is correct?

  • A: Humans require fewer essential elements than plants.
  • B: Oxygen, carbon, hydrogen, and nitrogen collectively make up about 96.3% of the human body's mass.
  • C: Trace elements are required in large quantities for normal bodily function.
  • D: Arsenic is an essential trace element beneficial for human health.

Explanation

The text states: "Just four elements—oxygen O , carbon C , hydrogen H , and nitrogen N —make up approximately 96% of living matter." Table 2.1 provides precise percentages: Oxygen 65.0% , Carbon 18.5% , Hydrogen 9.5% , Nitrogen 3.3% . Summing these gives 65.0 + 18.5 + 9.5 + 3.3 = 96.3%. This confirms that these four elements account for 96.3% of the human body's mass.