Download Unit 3 Problem Set Unit3_ProblemSet

Biology 100
NAME:
DATE:
Problem Set for Unit 3
PERIOD:
1. If a particular gene has a sequence that is 21% A (among A, C, G, and T), what percent can be deduced to be
made up of G?
2. DNA has many properties that allowed us to isolate it in lab. For each property listed, describe how we
exploited that property in the DNA isolation.
a) VERY long
b) Negatively charged
c) Soluble in water
3. Use the following terms to correctly describe how information in DNA determines our response to drugs
using CYP3A4 as an example:
DNA sequence
Protein sequence
Protein function
Neuron function
4. Two people mate who are both HETEROZYGOUS for blood type A – a trait that shows Mendelian (not incomplete)
dominance.
a) What are their phenotypes? What are their genotypes?
b) What phenotypes will be seen in what PROPORTIONS for their kids (assuming an infinite number of kids)?
c) What type(s) of kid would they NOT be likely to have?
5. Tasting a bitter chemical is probably NOT a dominant trait but an incompletely dominant trait. Super tasters have two
contributing alleles, tasters only one and non tasters – no contributing alleles. Whistling is a recessive trait controlled by a
gene that shows Mendelian dominance.
a)
b)
c)
d)
What is the genotype of a Taster who can whistle?
What is the genotype of a Taster who cannot whistle, but whose mother could?
If the people described in a) and b) mate, what proportion of their children will be whistlers?
If the same people mate, what proportion of their children will whistle and be non-tasters?
6. Two people who are heterozygous (Rr x Rr) mate. Among their kids there are THREE different phenotypes.
How is the trait controlled by gene R inherited?
7. Congenital amusia is a condition wherein affected individuals have absolutely NO musical abilities, can’t tap out
rhythms, can’t carry a tune, etc. This trait is inherited as a recessive trait. Make a pedigree that would show how this trait
is inherited and shows clearly that it is NOT dominant.
8. If identical twins are concordant for Congenital amusia, does this alone show that the trait is genetically controlled?
Careful!
9. If QqRrSs x qqRrSS, and all three genes contribute additively to a trait solve the following questions:
a) Make three Punnett squares for this mating
b) Complete a branch diagram for the mating
c) Determine the probability of all genotypes for children from this mating
d) Make a distribution graph for the possible phenotypes of the children from this mating.
Biology 100
Problem Set for Unit 3
10. Examine the accompanying pedigree where a solid black symbol shows someone with severe drug allergy, a striped
symbol shows someone with a mild allergy, and an open symbol shows someone with no drug allergy.
a) Assuming this trait is controlled by ONE gene, what can we assume about the way this gene controls the
phenotype of drug allergy?
b) What is the genotype of the person designated by the arrow?
c) If this woman were to have a child with a strong drug allergy, what can we assume about her mate?
d) Is it possible for this pedigree to represent a trait controlled by two genes?