MENDELIAN'S PRINCIPLE

• pair of similar or contrasting characters. Expression for traits. Example: Black Hair (B) and Brown Hair (b)

  Allele
• • If both alleles from parents are the same Example: BB (Black hair) and bb (brown hair)

  Homozygous
• If both alleles from parents are different Example: Bb (Black hair)

  Heterozygous
• • genetic make-up of an organism Example: Homozygous Black hair

  Genotypes
• external appearance or expression of the genetic makeup

  Example: Black Hair

  Phenotypes
• refers to the parental generations

  P1
• refers to successive generation or Fillial generation.

  F1
• • Father of Genetics
  • Austrian Monk
  • Studies of inheritance of traits in pea plants
  • Heredity refers to the transfer of traits

  Gregor Mendel
• states that in every organism, there is a pair of factors or genes which control the appearance of a particular trait

  Law of Dominance
• One allele is a dominant trait, while the other is a recessive trait.

  Law of Dominance
• The dominant trait is represented by a big letter and a small letter for the recessive trait.

  Example: Black hair is B and Brown hair is b

  Law of Dominance
• The dominant traits hide or mask the appearance of the recessive trait. Example: Bb (Black hair)

  Law of Dominance
• states that all pairs of genes for all the traits of an organism segregate or separate from each other during meiosis 


  Law of Segragation
• finding out the inheritance pattern of a trait between two single organisms

  Monohybrid Crossing
• states that the distribution or assortment of one pair of genes is independent of the distribution of the other pair.

  Law of Independent Assortment
• • Homozygous Tall and Homozygous Short;
  • Homozygous Black
  • Homozygous Brown Tall (T)
  • Short (t) ; Black hair (B) Brown Hair (b)

  Law of Independent Assortment
• • Genotype: 1 BBTT, 2 BBTt, 1 BBtt, 2 BbTT, 4 BbTt, 2 Bbtt, 1 bbTT, 2 bbTt, 1 bbtt
  • GR: 1:2:1:2:4:2:1:2:1

  Law of Independent Assortment
• • Phenotype: 9 Black Tall
  • 3 Black Short,
  • 3 Brown tall,
  • 1 brown short
  • PR: 9:3:3:1
  • Fractional Ratio: 9/16:3/16:1/16

  Law of Independent Assortment