AQA A Level Biology复习笔记4.1.7 Non-Coding DNA

Non-Coding DNA


  • The genome within eukaryotic cells contains many non-coding sections of DNA
    • Non-coding DNA does not code for any amino acids


  • Non-coding DNA can be found between genes, as non-coding multiple repeats
    • This means they contain the same base sequences repeated multiple times


  • Non-coding DNA can also be found within genes, as introns
    • The coding exons can be separated by one or more introns


  • During transcription, eukaryotic cells transcribe the whole gene (all introns and exons) to produce pre-mRNA molecules
  • Before the pre-mRNA exits the nucleus the non-coding sections (introns) are removed and the coding sections (exons) are joined together in a process called splicing



The RNA molecule produced from the transcription of a gene contains introns that must be removed before translation can occur.