Parental (P) generation

          F₁ generation

          F₂ generation

Allele

Homozygous

          True breeding

Heterozygous

Principle of dominance

Dominant

Recessive

Genotype

Phenotype

Punnett square

Gametes

Monohybrid cross

Test cross

Dihybrid cross

Multiple alleles

          Codominant

Erythroblastosis fetalis

Polygenic inheritance

Phenylketonuria   PKU

          Phenylalanine (Amino acid) ------> Tyrosine (Amino acid)

Sickle cell anemia - SS     Ss     ss

          Heterozygote advantage - Ss

Cystic fibrosis

Huntington's disease

		 	  	 Genotype             	         Phenotype

Homozygous Dominant	Bent / Bent  (BB)			- Bent little fingers 
 ( True Breeder )  

Heterozygous		Bent / Straight  (Bb)	 	- Bent little fingers
         
Homozygous Recessive	Straight / Straight  (bb) 	- Straight little fingers
 ( True Breeder )

     Possible Genotype		 Phenotype

	AA, AO				Type A blood
	BB, BO				Type B blood
	AB (Codominant)		Type AB blood
	OO				Type O blood



   LIGHT	      		MEDIUM		   	      DARK

  aabbccdd  --------->  AaBbCcDd  ------------>  AABBCCDD

Mouse can be Black or Tan

Black is dominant



Their hair can be Straight or Curly

Straight is dominant



Cross 2 mice that are heterozygous for both traits - dihybrid cross



Genotypes of the Parents = ___________________________



Gametes of the Parents = ____________________ 	



How many are:



Black with straight hair _____________



Black with curly hair _______________



Tan with straight hair ______________



Tan with curly hair ________________