Today Inheritance for 1 gene One of the

Today: Inheritance for 1 gene One of the key differences between experts and novices is an experts ability to recognize important information from less important information.

Fig 12. 3 {Producing gametes} Sexual reproduction creates genetic diversity by combining DNA from 2 individuals, but also by creating genetically unique gametes. {Producing more cells}

haploid X 23 in humans diploid X 23 in humans Inheritance = The interaction between genes inherited from Mom and Dad.

Do parents’ genes/traits blend together in offspring?

Fig 13. 4 In many instances there is a unique pattern of inheritance. Traits disappear and reappear in new ratios.

Genotype Phenotype

Human blood types Box 44. 2

Box 44. 2 One gene with three alleles controls carbohydrates that are found on Red Blood Cell membranes A A A RBC A A Allele A = A carbs B B B RBC B B B Allele B = B carbs Allele O = no carbs

Human blood types Box 44. 2

We each have two versions of each gene… A So A A RBC A A Genotype could be A and A OR A and O

Recessive alleles do not show their phenotype when a dominant allele is present. A A A RBC A A Genotype could be A and A OR A and O

What about… RBC Genotype = ? ?

What about… RBC Genotype = OO

What about… B A A B A RBC B A B B A

What about… B A A B A RBC B A B Genotype = AB B A

Human blood types Phenotype Genotype e AA or AO BB or BO AB OO Box 44. 2 Result of transfusion

If Frank has B blood type, his Dad has A blood type, And his Mom has B blood type… Should Frank be worried?

Mom=B blood possible BB or BO genotypes Dad=A blood AA or AO

possible genotypes Mom=B blood Dad=A blood BB or BO AA or AO Gametes all B / 50% B and all A / 50% A and 50% O

possible genotypes Mom=B blood Dad=A blood BB or BO AA or AO Gametes all B / 50% B and all A / 50% A and 50% O Frank can be BO = B blood …no worries

Grandparents AB and AB Mom=B blood possible BB or BO genotypes Gametes all B / 50% B and 50% O Frank can be BO or BB = B blood Dad=A blood AA all A …Uh-Oh

Some simple dominant/recessive relationships in humans Dom. Rec. Dom.

We can also predict the future Fig 2. 12

Inheritance of blood types Mom = AB Dad = AB

Inheritance of blood types Mom = AB Gametes: A or B Dad = AB A or B

Inheritance of blood types Mom = AB Gametes: A or B Dad A or B A AA Mom or B AB Dad = AB AB BB Chance of each phenotype for each offspring 25% AA 50% AB 25% BB

Testcross: determining dominant/ recessive and zygosity

Sickle-cell anemia is caused by a point mutation Fig 16. 21

Sickled and normal red blood cells

Sickle-Cell Anemia: S=sickle-cell A dominant or recessive allele? H=normal Mom = HS Dad H or S H HH Mom or S HS HS SS Dad = HS possible offspring 75% Normal 25% Sickle-cell

Coincidence of malaria and sickle-cell anemia

Sickle-Cell Anemia: S=sickle-cell A dominant or recessive allele? H=normal Mom = HS Dad H or S H HH Mom or S HS HS SS Dad = HS possible offspring Oxygen transport: 75% Normal 25% Sickle-cell Malaria resistance: 75% resistant 25% susceptible

Variation in pea shape and color

Phenotype Genotype Fig 13. 5

The inheritance of genes on different chromosomes is independent. Fig 13. 5

Approximate position of seed color and shape genes in peas Y y Gene for seed color Fig 13. 8 r Chrom. 1/7 R Chrom. 7/7 Gene for seed shape

The inheritance of genes on different chromosomes is independent: independent assortment Fig 13. 8

Fig 13. 8 meiosis II

The inheritance of genes on different chromosomes is independent: independent assortment Fig 13. 8

Fig 13. 5