can anyone help me with my biology homework?

Question

2. Another hair trait (hair texture) is controlled by the two alleles F and f. The allele F is dominant for straight hair and s is recessive for curly hair.
a. What two genotypes result in straight hair?
b. What genotype results in curly hair?
c. If a man who is heterozygous for straight hair marries a woman who is heterozygous for straight hair, what is the chance they will have a child with straight hair? (Show your work, i.e. want to see a Punnett Square.)


3. Considering the two pairs of alleles B, b and F, F, show below all the genotypes that would result in dark, straight hair. Hint there are four.



4. Jack has the genotype Bbff and his wife Jill has the genotype bbFf.
a. What is Jack’s phenotype?
b. What is Jill’s phenotype?
c. What would Jack’s gametes look like?
d. What would Jill’s gametes look like?
e. Show the dihybrid cross resulting from Jack and Jill. (Please show all work, i.e. Punnett Square.)

Answer 1

2 a.  Genotypes FF and Ff result in straight hair.

 

b.  Genotype ff results in curly hair.

 

c.  Each parent produces the  gametes  F and f.  Possible genotypes of the their progeny are FF:Ff:ff in the ratio 1:2:1.  So there is a 1/4  or 0.25 chance that they will have a child with straight hair. 

 

3.  Straight hair genotypes are FF and Ff. Dark hair genotype is BB, Bb.  

    Possible combinations are FFBB, FFBb, FfBB, FfBb.

 

4.  

a. Bbff:  Dark Curly

b. bbFf: Blond Straight 

c. Gamates: Bf and bf

d. Gamates: bF and bf

e.  Use the Punnett square to find the possible genotypes of the dihybrid cross ( BbFf, Bbff, bbFf, bbff)