Bellringer Problems: PKU

37
Bellringer Problems: PKU

description

Bellringer Problems: PKU. Bellringer Problems: Huntington’s Disease. Bellringer Problems:CF. Non- Mendelian Genetics. Modifications to the expected Mendelian ratios…. For example – in snapdragons, cross a red flowered plant with a white flowered plant… - PowerPoint PPT Presentation

Transcript of Bellringer Problems: PKU

Page 1: Bellringer  Problems: PKU

Bellringer Problems: PKU

Page 2: Bellringer  Problems: PKU

Bellringer Problems: Huntington’s Disease

Page 3: Bellringer  Problems: PKU

Bellringer Problems:CF

Page 4: Bellringer  Problems: PKU

Non-Mendelian Genetics

Page 5: Bellringer  Problems: PKU
Page 6: Bellringer  Problems: PKU

Modifications to the expected Mendelian ratios…

For example – in snapdragons, cross a red flowered plant with a white flowered plant…

Mendel predicted you would end up with…

Page 7: Bellringer  Problems: PKU

But he was wrong…You get all *pink* flowers!

Why?

Page 9: Bellringer  Problems: PKU
Page 10: Bellringer  Problems: PKU

Incomplete Dominance

Page 11: Bellringer  Problems: PKU

Incomplete DominanceIntermediate phenotype in

heterozygotes…

It is a “blend” between the dominant and recessive forms of the gene

Page 12: Bellringer  Problems: PKU

Sample ProblemIn horses, the dominant D allele allows

coat color to fully develop. The d allele dilutes, or weakens, coat color. When a chestnut (brown) horse is crossed with a cremello (nearly white) horse, their offspring are palominos (gold with white manes and tails)

Page 13: Bellringer  Problems: PKU
Page 14: Bellringer  Problems: PKU

Sample Problem ContinuedWhat is the genotype of…• A chestnut horse? ______________• A cremello horse? ______________• A palomino horse? ______________What would be the expected

phenotypic ratios of a cross between two palomino horses?

Page 15: Bellringer  Problems: PKU
Page 16: Bellringer  Problems: PKU

Another example from your dragons…

Page 17: Bellringer  Problems: PKU

The case of the missing purebred…

Manx cats are born tailless. But if you cross two Manx cats you will never get 100% Manx kittens. Never ever ever.

Page 18: Bellringer  Problems: PKU

Lethal Alleles

Page 19: Bellringer  Problems: PKU

Lethal AllelesThe homozygous condition is lethal…

Page 20: Bellringer  Problems: PKU

Sample ProblemAchondroplasia, a form of dwarfism, is

caused by the dominant allele A. Embryos with the genotype AA do not survive. Suppose that two people with achondroplasia get married and have children.

What phenotypic ratio would you observe in the couple’s children?

Page 21: Bellringer  Problems: PKU
Page 22: Bellringer  Problems: PKU

The case of the orange cows…

In cattle, red hair is dominant to white hair…but when you cross a red bull with a white cow, you get…

ROAN CATTLE

Page 23: Bellringer  Problems: PKU

CodominanceDefinition:

Page 24: Bellringer  Problems: PKU

Codominance• BOTH alleles are expressed at the same

time • Heterozygous = both phenotypes

expressed equally

Page 26: Bellringer  Problems: PKU

Practice ProblemAndalusian chickens– Black feathers is codominant with white

feathers– Heterozygous = __________________________

Page 27: Bellringer  Problems: PKU

FB = black and FW = white

Black x white FBFW x FBFW

Page 28: Bellringer  Problems: PKU
Page 29: Bellringer  Problems: PKU
Page 30: Bellringer  Problems: PKU

It’s a guy thing, you wouldn’t understand…

Page 31: Bellringer  Problems: PKU

Sex-linkedDefinition:

Page 32: Bellringer  Problems: PKU

Sex-linkedPattern of inheritance for genes

located on X (sex) chromosome. Rarely on Y…

Page 33: Bellringer  Problems: PKU

Sex-linked GenesExample: ColorblindnessXB, Xb, YGenotypes? Phenotypes?

Page 34: Bellringer  Problems: PKU

PracticeColorblindness:Normal Male x Carrier Female

Genotypes Phenotypes

Page 35: Bellringer  Problems: PKU

Sex-linked GenesExample: HemophiliaXH, Xh, YGenotypes? Phenotypes?

Page 36: Bellringer  Problems: PKU

PracticeHemophilia:Hemophiliac Male x Carrier Female

Genotypes Phenotypes

Page 37: Bellringer  Problems: PKU

Blood Types