Which six elements are most commonly found in living organisms and are essential for life?

• A. Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur
• B. Calcium, Potassium, Sodium, Chlorine, Magnesium, and Iron
• C. Phosphorus, Sulfur, Calcium, Iron, Zinc, and Copper
• D. Carbon, Hydrogen, Helium, Oxygen, Nitrogen, and Neon

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the context of the question. The problem is asking about the six elements most commonly found in living organisms and essential for life. These elements are often referred to as CHNOPS, which stands for Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.
2. Step 2: Recall the importance of each element in biological systems. For example, Carbon is the backbone of organic molecules, Hydrogen is part of water and organic compounds, Nitrogen is crucial for amino acids and nucleotides, Oxygen is essential for cellular respiration, Phosphorus is a key component of DNA and ATP, and Sulfur is found in certain amino acids and vitamins.
3. Step 3: Compare the options provided in the question. Look for the set of elements that matches CHNOPS. Eliminate options that include elements not commonly found in living organisms or not essential for life, such as Helium and Neon.
4. Step 4: Recognize that the correct answer is the set containing Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur, as these are universally recognized as the six essential elements for life.
5. Step 5: Confirm your understanding by reviewing the roles of CHNOPS in biological processes, ensuring you can explain why these elements are fundamental to life and why other elements listed in the options are not part of this essential group.