Download Genetics problems assignment

GENETICS PROBLEMS
1. A man with a widow’s peak (WW) marries a woman with a continuous hairline (ww). What kind of hairline will
their children have?
a. Allelic composition of gametes produced: male = _______________, female = _______________
b. Show the cross here:
c. Children’s: genotype(s) = ______________________, phenotype(s) = ___________________
2. Suppose one of the males from the above problem marries a women who is heterozygous (Ww). What type of
hairline will their children have?
a. Allelic composition of gametes produced: male = _______________, female = _______________
b. Show the cross here:
c. Children’s: genotype(s) = ______________________, phenotype(s) = ___________________
3. A woman is homozygous dominant for short fingers (FF). She marries a man who is heterozygous for short
fingers (Ff).
a. Allelic composition of gametes produced: male = _______________, female = _______________
b. Show the cross here:
c. Will any of their children have long fingers(ff), yes or no? _______________
d. Could any of the grandchildren of the above couple potentially have long fingers? Why or why not?
(Hint: It may help to show any possible crosses.)
4. Jane and John are expecting a baby and know that they are both carriers (i.e. heterozygous) of cystic fibrosis
(Cc). What is the probability that their child will have cystic fibrosis (cc)? What is the probability that their child
will be a carrier of cystic fibrosis?
Chance of child being:
__________%_ disease free; genotype = _______________
__________%_ cystic fibrosis carrier; genotype = _______________
__________%_ cystic fibrosis; genotype = _______________
5. You have freckles and dimples (FfDd). Your significant other has freckles but no dimples (Ffdd). What is the
chance your child would have both recessive phenotypes: no freckles and no dimples (ffdd)? (Hint: do a dihybrid
cross using the foil method)
a. Allelic composition of gametes produced: you = _______________, other = _______________
b. Show the cross here:
c. % no freckles and no dimples: _________________________
6. Hemophilia is a recessive genetic disorder whose allele, which we’ll call a, is located on the X chromosome.
What are the chances that parents with the following genotypes will have a child with hemophilia?
a. XAXA x XaY
b. XAXa x XaY
c. XAXa x XAY
d. XaXa x XAY
7. If blue flowers(B) are dominant to white flowers (b), what are the genotypes of the parents in the following
genetic cross: blue flower x white flower yields only blue-flowered offspring?
Blue flower genotype: ____________
White flower genotype: ____________
8. The fruit pods of peas can be yellow or green. In one of his experiments, Mendel crossed plants that were
homozygous for the allele for yellow fruit pods with plants that were homozygous for the allele for green fruit
pods. All fruit pods in the F1 generation were green. Which allele is dominant, the one for yellow or the one for
green? Briefly explain why, it may help to show the crosses for each.
9. Color-blindness is a sex-linked gene carried on the X chromosome. A color-blind man and his wife, with normal
vision, have a color-blind daughter. What is the probability that their newborn son will also be color blind?
10. Use this pedigree and the given phenotypes (table below) to determine the genotypes for each of the following
individuals. The trait is recessive.
Female
Male
Affected
Unaffected