State that a polypeptide is coded for by a gene and that a gene is a sequence of nucleotides that forms part of a DNA molecule

• Definition of a Polypeptide in Relation to a Gene:
  • A polypeptide is a chain of amino acids coded for by a gene.
  • The sequence of nucleotides in a gene determines the sequence of amino acids in a polypeptide.
• Definition of a Gene:
  • A gene is a sequence of nucleotides that forms part of a DNA molecule.
  • This sequence encodes information for making:
    • A polypeptide chain (protein) via transcription and translation.
    • Alternatively, an RNA molecule with functions other than direct protein coding (sometimes referred to as RNA genes).

Supporting Quotes from the Provided Web Search Results:

1. Polypeptide Coded for by a Gene:
   • “…the sequence of amino acids built according to the sequence of nucleotides forms a polypeptide chain…” (Gene transcription and translation)
   • “…one gene being responsible for the assembly of one enzyme, or one polypeptide chain. This is known as the one gene–one enzyme hypothesis.” (Gene transcription and translation)
2. Gene as a Sequence of Nucleotides in a DNA Molecule:
   • “…a gene is a DNA sequence… that specifies one or more sequence-related RNAs/proteins…” (Putting it all Together: Toward a New Definition of the “Gene”)
   • “…a discrete sequence on a DNA molecule that encodes a polypeptide chain.” (The Evolving Definition of the Term “Gene”)

Relationship to Previous Questions:

• This answer reinforces the concept from the previous question about gene mutations potentially altering polypeptides, by highlighting the gene-polypeptide coding relationship.
• It also complements the earlier questions about DNA structure (bases, purines, pyrimidines) and transcription (template strand), as it discusses the functional aspect of genes within the DNA molecule.