Genes

• A gene is a section of DNA that contains the coded information to make polypeptide or RNA
• Dna determines the chemical reactions within a cell
• A codon is 3 bases, a codon produces an amino acid
• Humans use 21 amino acids arranged in a combination, building 1000's of different proteins
• DNA uses degenerate code

  There are 64 codon possibilties hence 64 amino acid possibilities however only 21 amino acids are required, therfore some codon code for the same amino acid
• Genes contain stop and start codons
• DNA is non over-lapping because each DNA base is Read once
• Genes end with 1 of 3 stop codons
• DNA is universal because all life contains DNA
• Amino acids are generated in tripleys
• Allele is one of a number of different forms of the same gene
• Alleles have different DNA sequences
• You inherit 2 copies of every gene
• Non coding section of a gene is an intron