A Level Biology Practice Exam

What describes a large molecule made up of many nucleotides?

1. Nucleotide

2. Polynucleotide

3. Mononucleotide

4. Amino acid

The correct answer is: Polynucleotide

The description of a large molecule made up of many nucleotides corresponds to a polynucleotide. Polynucleotides are long chains composed of multiple nucleotide units linked together through phosphodiester bonds. Each nucleotide itself consists of a sugar, a phosphate group, and a nitrogenous base. When many of these nucleotides are connected, they form the backbone of nucleic acids such as DNA and RNA. The structure allows them to carry genetic information, which is crucial in biological systems. In contrast, a single nucleotide refers to just one unit, and a mononucleotide is a term typically used to describe that single, independent nucleotide. Amino acids, on the other hand, are the building blocks of proteins, not nucleic acids, and do not consist of nucleotides.