Launch Mr. McCaffrey is colorblind, as is his father.

His mother is color normal, but we don’t know whether she is a carrier or not. A. What is McCaffrey’s genotype B. What is the genotype of McCaffrey’s father? C. Complete a cross/punnett square to figure out

his mother’s genotype D. Explain whether or not the fact that his father

has the disease is important

Identify the disease below:

Inheritance of Genes:

What does it mean to be a carrier? A person who is a carrier is heterozygous

(Aa). They carry the gene for the disease (a);

BUT they do not have the disease because they are protected by the dominant gene (A).

We use Punnett Squares to determine what the probability of being a carrier

We call this -> a monohybrid cross

AA Aa

Aa aa

A

a

A

aFather

Mother

Dihybrid Crosses Dihybrid crosses let you look at two traits at

the same time. Sixteen boxes instead of four

Mendel’s Law of Segregation According to Mendel’s law, each gamete

will only have one version (allele) of each chromosome

Essentially all gametes are haploid instead of diploid and each gamete has one version of each chromosome from 1-23

Mendel’s Law of Independent Assortment

According to Mendel’s law, which allele goes into each gamete, is random for each chromosome.

Distributive Properties We use distribution to determine the gamete

possibilities:

AaBb

Possible gametes: AB, Ab, aB, ab

What are the possible gametes for

DdFF?

Dihybrid Crosses The ratio we use for a dihybrid involves 4 different

possibilities

Dominant for both traits (A_B_) Dominant for the first trait, but not the second

(A_bb) Dominant for the second trait but not the first

(aaB_) Recessive for both traits (aabb)

AARR AARr AaRR AaRr

AARr AArr AaRr Aarr

AaRR AaRr aaRR aaRr

AaRr Aarr aaRr aarr

AR araRAr

ar

aR

Ar

ARDominant for

both traits

Dominant for one, recessive for the second

Dominant for the second, recessive for

the first

Recessive for both traits