genetics

• Asexual reproduction


  One parent, no gametes joining, no mixing of genetic information
• Asexual reproduction


  • Leads to clones of parent
• Organisms that reproduce asexually

  • Bacteria
  • Some plants
  • Some animals
• Meiosis

  1. Chromosomes pulled apart (mix of mum and dad)

  2. 4 nuclei formed
• Gene


  Short section of DNA that codes for many amino acids which fold together to make a protein
• Genome


  All genetic information of a single organism
• Extracting DNA from fruit

  1. Use salt, cold water and washing up liquid in beaker

  2. Place in water bath for 15 minutes

  3. Pulpense a kiwi and add to solution

  4. Filter the solution with filter paper
• Protein synthesis

  1. mRNA nucleotides join together creating an mRNA strand

  2. RNA polymerase binds to non-coding DNA

  3. Two DNA strands pull apart, mRNA nucleotides match to complementary bases

  4. mRNA moves to ribosomes

  5. Amino acids brought to ribosomes by tRNA

  6. Amino acids connect to form polypeptide which folds to form protein
• Mutation


  • Genetic variant in the coding DNA that alters the sequence of amino acids, affecting the protein made
  • Genetic variant in the non-coding DNA that affects how much mRNA can be formed, affecting the structure of the final protein
• Homozygous - both inherited alleles are the same
• Heterozygous - one allele is dominant and the other is recessive
• XY - male, XX - female
• O allele is recessive, A and B alleles are dominant, so only OO genotypes make O blood
• The Human Genome Project improved understanding of genes linked to diseases, helped in treatment of inherited diseases, and helped trace human migration patterns