Genetics - Multiple Alleles

GENETICS Multiple Alelles Robert Perry MALIBU HIGH SCHOOL

MULTIPLE MULTIPLE ALLELES ALLELES

MULTIPLE MULTIPLE ALLELES ALLELES Most human genetic traits are determined by more than just two (dominant and recessive) alleles.

HUMAN BLOOD

Type A Type B Type AB Type O

Human blood types are determined by multiple alleles.

45% of the U.S. population are type O, 42% type A, 10% type B and 3% type AB

Here’s the way it works: PHENOTYPE type A type B type AB type O

GENOTYPE(S) AA or AO BB or BO AB OO

MULTIPLE MULTIPLE ALLELES ALLELES BLOOD TYPE GENETICS PROBLEMS

1.

One parent is type O, the other is type AB.

1.

Type AB

AB

Type O

OO First: Write the parent’s genotypes.

Type O

1.

OO

O Type AB

AB

A B

O Second: Make the gametes.

1.

Type O

OO

O O Type AB A AO AO AB B BO BO

Third: Match up and find the offspring’s genotypes.

1.

Type O

OO

O O Type AB A AO AO AB B BO BO

Fifth: Count ‘em up.

2/4 or 50% will be type A 2/4 or 50% will be type B

2.

Could a man with type B blood and a woman with type AB produce a child with type O blood?

2.

Could a man with type B blood and a woman with type AB produce a child with type O blood?

Possible genotypes The possible genotypes of a man with blood type B are BB or BO, and the genotype of a woman with blood type AB is AB.

type AB AB Type B

A B

B

type AB AB Type B

AB BB

BB

BO B

AB BB

A

B

B AB

BB

O AO

BO

type AB AB Type B

A B

B

type AB AB Type B

AB BB

BB

BO B

AB BB

A

B

B AB

BB

O AO

BO

A type O child is impossible.

REVIEW CHECKPOINT:

REVIEW CHECKPOINT: 1. What is meant by “multiple alleles” ?

REVIEW CHECKPOINT: 1. What is meant by “multiple alleles” ?

2. Name one human trait controlled by multiple alleles.

REVIEW CHECKPOINT: 1. What is meant by “multiple alleles� ?

2. Name one human trait controlled by multiple alleles.

3. What are the 4 main human blood types ?

REVIEW CHECKPOINT: 1. What is meant by “multiple alleles� ?

2. Name one human trait controlled by multiple alleles.

3. What are the 4 main human blood types ?

4. What are the possible blood types for the offspring if both parents are type AB ?

REVIEW CHECKPOINT: 1. What is meant by “multiple alleles� ?

2. Name one human trait controlled by multiple alleles.

3. What are the 4 main human blood types ?

4. What are the possible blood types for the offspring if both parents are type AB ?

5. What are the possible blood types for a father, if both the mother and son are type A ?