What are the polynucleotide chains known as DNA or RNA collectively called?

The correct answer refers to the fundamental structure of genetic material within living organisms. Polynucleotide chains, which are composed of nucleotide monomers joined together, are classified as nucleic acids. This classification encompasses DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), both of which play critical roles in the storage and expression of genetic information. Nucleic acids consist of long chains of nucleotides that form the backbone of these molecules, enabling them to carry essential genetic instructions necessary for the development and functioning of all living organisms.

In contrast, the other choices refer to more specific concepts. Chromatin is a complex of DNA and proteins that forms the chromosomes within the nucleus of eukaryotic cells, serving primarily to package DNA into a more compact, dense shape. Gene material is a less precise term that could refer to segments of DNA that code for proteins, but it does not encompass the entire structure or function of nucleic acids. Ribosomal DNA specifically refers to the DNA that encodes ribosomal RNA, a component of ribosomes, and does not represent the broader category of nucleic acids.