inheritance

• chromosome= long DNA molecule containing genes

  genes= sequence of bases which code for a single polypeptide chain

  allele= different versions of the same gene
• homozygous and heterozygous

  • homologous pairs of chromosomes= pair of chromosomes that match in size and shape and contain same genes at same loci- one chromosome from mum and one from dad
  • homo= 2 identical alleles at a locus
  • hetero=2 different alleles at a locus
• genotype= alleles of a gene posses by an individual

  phenotype= observable charactersitics of an organism
• dominant= always expressed in phenotype no matter which other alleles present

  recessive=only expressed in phenotype if no dominant allele is present, only expressed in homozygous recessive individuals
• incomplete dominance

  • trait from a dominant allele not completely expressed over trait of a recessive allele

  -recessive allele 'dilutes' effects of dominant allele

  • both alleles influence the phenotype in heterozygous individuals- giving rise to 3rd phenotype