Scientific heredity word problems? PLEASE HELP?

Question

1. A woman who is homozygous for curly hair marries a man with straight hair. What are the possibilities of their children's hair? Curly hair is dominant over straight. Show genotypes and phenotypes.

2. Rachel has type B blood and knows her mother is type AB blood. Her father has type A blood. What is Rachel's genotype? What is Rachel's father's genotype? Show a punnet for proof.

3. Brown hair is dominant over blonde. Brown eyes are dominant over blue. Cross a heterozygous brown hair, blue eyed person with a blonde, heterozygous brown eyed person. Show genotypes and phenotypes.

Answer 1

1.) Take C for dominant and c for recessive.

Woman= CC (homozygous dominant)

Man= cc (heterozygous recessive, th only way to be straight haired)

      F x M

     cc  CC

    c,c  C,C

      C   C

c   Cc Cc

c   Cc Cc

Genotypic Ratio= 4:0 or 1:0

Phenotypic Ratio= 4:0 or 1:0

The only genotype will be Cc and all of their offsprings will be curly haired.

2.) Mother= AB

     Father= A?

(If her father has a phenotype of AA, then it will not be possible for Rachel to have a bloodtype of B because the only genotype when crossed is AB and AA, could it be possible that it is AO ( bloodtype O  is a recessive, because A and B are both dominant)?

      F  x  M

    AO    AB

   A, O  A, B

       A     O

A   AA   AO

B   AB   BO

Genotypic Ratio= 1:1:1:1

Phenotypic Ratio=  1:1:1:1

It is possible that Rachel's genotype is BO, and her father's genotype is AO. (A and B are dominant over O)

3.) B= brown, b= blonde, E= brown eyes, e= blue eyes

For example:

        F     x      M

     Bb ee     bb Ee

    B,b e,e   b,b E,e

Determine all possible combinations of alleles in the gametes for each parent.



F= Be Be be be

M= bE be bE be

To simplify:

F= Be, be

M= bE, be

          Be         be

bE   BbEe   bbEe

be   Bbee    bbee

Possible Genotypes are: BbEe,   bbEe,   Bbee,    bbee

Genotypic Ratio= 1:1:1:1

Phenotypic Ratio= 1:1:1:1

1= Brown Hair Brown Eyes

1= Brown Hair Blue Eyes

1= Blonde Hair Brown Eyes

1= Blonde Hair Blue Eyes

I hope I got it correctly.