AQA A Level Biology复习笔记4.1.5 Genetic Loci

Genetic Loci

 

Genes, loci and alleles

  • The DNA contained within chromosomes is essential for cell survival
  • Every chromosome consists of a long DNA molecule that codes for several different proteins
  • A length of DNA that codes for a single polypeptide or protein is called a gene
  • The position of a gene on a chromosome is its locus (plural: loci)
  • Each gene can exist in two or more different forms called alleles
  • Different alleles of a gene have slightly different nucleotide sequences but they still occupy the same position (locus) on the chromosome

 

Chromosomes-showing-gene-and-loci

Five different genes found at five different loci

 

 

转载自savemyexams

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