OCR A Level Biology - Nucleotides and
Nucleic Acids Questions & Answers
Nucleotide - ANSWERSMonomer that forms DNA and has a phosphate group, a sugar,
and a nitrogen-containing base.
DNA - ANSWERSA complex molecule containing the genetic information that makes up
the chromosomes.
RNA - ANSWERSA single-stranded nucleic acid that passes along genetic messages.
Purines - ANSWERSNitrogenous bases that have a double ring of carbon and nitrogen
atoms, such as adenine and guanine.
Pyrimidines - ANSWERSNitrogenous bases that have a single ring of carbon and
nitrogen atoms, such as cytosine and thymine
ADP - ANSWERSAdenosine diphosphate; a molecule that ATP becomes when it gives
up one of its three phosphate groups.
ATP - ANSWERSAdenosine triphosphate; the main energy source that cells use for
most of their work.
Polynucleotide - ANSWERSA polymer consisting of many nucleotide monomers in a
chain; nucleotides can be those of DNA or RNA.
Phosphodiester bond - ANSWERSThe bond between the phosphate of one nucleotide
and two sugar molecules.
DNA helicase - ANSWERSAn enzyme that unwinds the DNA double helix during DNA
replication.
DNA polymerase - ANSWERSEnzyme involved in DNA replication that joins individual
nucleotides to produce a DNA molecule.
Nucleic Acids Questions & Answers
Nucleotide - ANSWERSMonomer that forms DNA and has a phosphate group, a sugar,
and a nitrogen-containing base.
DNA - ANSWERSA complex molecule containing the genetic information that makes up
the chromosomes.
RNA - ANSWERSA single-stranded nucleic acid that passes along genetic messages.
Purines - ANSWERSNitrogenous bases that have a double ring of carbon and nitrogen
atoms, such as adenine and guanine.
Pyrimidines - ANSWERSNitrogenous bases that have a single ring of carbon and
nitrogen atoms, such as cytosine and thymine
ADP - ANSWERSAdenosine diphosphate; a molecule that ATP becomes when it gives
up one of its three phosphate groups.
ATP - ANSWERSAdenosine triphosphate; the main energy source that cells use for
most of their work.
Polynucleotide - ANSWERSA polymer consisting of many nucleotide monomers in a
chain; nucleotides can be those of DNA or RNA.
Phosphodiester bond - ANSWERSThe bond between the phosphate of one nucleotide
and two sugar molecules.
DNA helicase - ANSWERSAn enzyme that unwinds the DNA double helix during DNA
replication.
DNA polymerase - ANSWERSEnzyme involved in DNA replication that joins individual
nucleotides to produce a DNA molecule.
