Mendelian Law of Inheritance

• Phenotype


  Observable physical or biochemical characteristics of an organism
• Genotype


  Genetic makeup of an organism
• Homozygous


  Having two identical alleles for a particular trait
• Heterozygous


  Having two different alleles for a particular trait
• Mendelian Laws of Inheritance

  • Law of Dominance
  • Law of Segregation
  • Law of Independent Assortment
• Law of Dominance


  Recessive alleles will always be masked by dominant alleles
• Dominant allele


  represented by uppercase letter (e.g. R, S)
• Recessive allele


  represented by lowercase letter (e.g s, r, b)
• Genotype


  Determines Phenotype
• Law of Segregation


  Pair of alleles for a heritable character segregates or separates during cell division so that only one of a pair will be received by each reproductive cell or gamete
• Law of Independent Assortment


  Two or more pairs of alleles segregate independently from one another
• Dominant allele


  represented by uppercase letter (e.g S, R, B)
• Incomplete dominance


  the phenotype of heterozygous individual is somewhere between the phenotype of homozygous dominant and homozygous recessive
• Co-dominance


  two dominant alleles affect the phenotype in separate distinguishible ways
• multiple alleles


  more than two alleles exist in a gene and are defined as a system