2.Genes and chromosomes

• Genes

  • sequence of DNA that codes for amino acid sequence for polypeptide/ functional RNA
• What is the role of functional RNA?

  RNA molecule other than mRNA, which perform special tasks during protein synthesis e.g. tRNA and ribosomal RNA which forms part of ribosomes
• Genome:

  • Complete set of genes in cell
• Proteome:

  • Full range of proteins that cell is able to produce
• Exons:

  • Coding regions of DNA for amino acids
• Introns:

  • DNA sections between exons which don’t code for amino acids- removed during protein synthesis. Involved in gene regulation
• Multiple repeats:

  Repeated DNA sequences that don’t code for amino acids
• Allele

  One or more alternative versions of the same gene
• Variations in the code

  Lead to different versions of the same polypeptide
• Homologous chromosomes

  Pairs of matching chromosomes
• Homologous chromosomes

  • Same size
  • Same genes (with variation!)
  • Loci with alleles coding for the same characteristic are found at the same fixed position