Question

a nasa science news item from december 2010 announced that scientists had identified a novel form of bacterial life from mono lake in california. unlike other living organisms, this bacterium utilizes arsenic in its dna and is able to live and grow without a supply of carbon, hydrogen, nitrogen, sulfur, oxygen, and phosphorus. these respective essential components for life are all:

• elements.
• atoms.
• macromolecules.
• amino acids.

Explanation:

Carbon, hydrogen, nitrogen, sulfur, oxygen, and phosphorus are all pure substances that cannot be broken down into simpler substances by chemical means, which is the definition of elements. Atoms are the basic units of elements, macromolecules are large molecules made of atoms/elements, and amino acids are building blocks of proteins (a type of macromolecule)—none of these categories fit the listed substances.

Answer:

elements.