Download Week 11 - UW Canvas

Biology 200, Autumn 2014
Problem Set Week 11
1. You would like to amplify the indicated region of the DNA sequence below.
a) What primers would you use in a PCR reaction? The primers must be at least 10
nucleotides long. (Be sure to indicate 5’ and 3’ ends of your primers!)
5’ AGCTCGTAGATCGGACAGCTGGATTCCGATAGCTAGTTCGGGGATCGATAAAATCGTAGCGTATAA 3’
3’ TCGAGCATCTAGCCTGTCGACCTAAGGCTATCGATCAAGCCCCTAGCTATTTTAGCATCGCATATT 5’
b) How long would the PCR product be using your primers? ____________________
c) Are your primers included in the PCR product? ______________________
2. In the following pedigree, the filled in
shapes indicate that the individual has a
recessive, autosomal trait. Using the allelic
notation "A" for the dominant allele and "a"
for the recessive allele, fill in the genotypes
for everyone in the pedigree. If you cannot
determine the definite genotype, fill in as
much information as you can.
3.
A
AB
A
B
AB
A
?
O AB
In the pedigree above, each individual's ABO blood type is indicated next to their symbol.
a) What is individual I-1's genotype for ABO? ________ II-2's genotype for ABO? ________
b) What is(are) all of the possible blood type(s) of individual III-3? ________
c) Which individuals could donate blood to individual II-2? ________
d) Which individual can accept blood from every other member of the family? ________
Biology 200, Autumn 2014
4. Look at the pedigree and answer these
questions about the filled-in symbol trait:
Problem Set Week 11
a) Could this be a dominant trait?
b) Could this be a sex-linked trait?
c) Could the darkened circles represent an allele at a polymorphic locus?
5. In a busy hospital several babies were born on the same day and got mixed up. In order to
make sure that they were placed with the correct parents, their alleles at 2 different
polymorphic loci were analyzed by PCR (be aware that parents may have had multiple
babies). One locus is indicated by the black bands and the other is indicated by the striped
bands.
1
2
3
4
mom
DNA
dad marker
Which baby(ies) could be the child(ren) of the mom AND dad presented on the gel? _______
The next question refers to information you will get during the last lab (you will only be
able to answer this after you have been to lab week 11):
6. Adelle and Briana have exactly the same genotype because they are identical twins – two
individuals created from a single fertilized egg. Assume Adelle has the same genotypes for
all her traits as you have determined them. What would be the probability that Briana
(assume she is a sister) would have matched Adelle’s genotype if they had been fraternal
twins? (To make this problem solvable, ignore the possibility of crossing over for the
linked traits and assume Ethyl is heterozygous for Rh). Consider the traits of ABO blood
type, Rh factor, MAM02, color blindness, and hemophilia.
Biology 200, Autumn 2014
Problem Set Week 11
7. Which of the following statements is(are) TRUE about PCR? (Circle all that apply)
A. Two different alleles from any locus must have different size PCR products.
B. Huntington's Disease was mapped to chromosome number 4 using PCR.
C. PCR cannot be performed on loci that have only 2 alleles in a population.
D. PCR does not require any knowledge of the sequence at or near the locus of interest.
8-11. Huntington’s disease is caused by an allele for the gene huntingtin which has an
increased number of CAG repeats. The protein encoded by the gene huntingtin is often
referred to as the Htt protein.
8. The CAG repeats are found in an exon / intron of the huntingtin gene. (Circle one)
9. Which levels of protein structure are different between normal Htt and Htt that causes the
disease phenotype? (Circle neither, one, or both)
Primary
Tertiary
10. In which of the following processes could an error occur to increase the number of CAG
repeats in a huntingtin allele and then be transmitted to the next generation? (Circle all
correct answers)
DNA replication
Transcription
Translation
11. The following table presents data for question 10:
d - wild-type huntingtin allele
D - disease huntingtin allele
0 - huntingtin allele deleted from genome
Genotype
dd
Dd
DD
d0
00
Phenotype of embryo
Normal
Normal
Normal
Normal
Gastrulation/Neurulation
incomplete
Phenotype of adult
Normal
Huntington’s Disease
Huntington’s Disease
Neurological problems (not HD)
Never reaches adulthood
True/False: Circle the right answer:
a)
T
F
Htt encoded by the D allele has lost all normal Htt function.
b)
T
F
An individual with genotype D0 will develop into an adult.
c)
T
F
An individual with genotype D0 will not have Huntington’s Disease.
d)
T
F
Normal adult neurological function requires a threshold level of Htt protein.
e) For question d, which genotype gives you evidence for your answer? __________
Biology 200, Autumn 2014
Problem Set Week 11
12. The DNA shown below will be used as a template for a PCR reaction. The arrows below
the template are spaced 10 base pairs apart to assist you with counting.
5' GTCTGTTAGCCATAGTTTCCCTATCCATCGACCTGAAAATCGGTATCTGGACTTTTAAGT 3'
3' CAGACAATCGGTATCAAAGGGATAGGTAGCTGGACTTTTAGCCATAGACCTGAAAATTCA 5'
What will be the length (in base pairs) of the double-stranded target PCR product after 30
rounds of PCR using the following two primers?
Primer 1:
5' ATTTTCAGGT 3'
Primer 2:
5' TTAGCCATAG 3'
13. Steve Scientist is a bungling student in Biology 200. He prepares an agarose gel to separate
his PCR fragments. When he connects the leads on his gel box, he plugs the red wire into
the black socket and vice versa. After 15 minutes, he realizes his mistake…
a) Where is his DNA?
b) How did he know there was a problem by looking at the GEL in the gel box?
14. Your thermocycler breaks down during a PCR run. You are not sure at which step the
reaction stopped, so you do an analysis on the DNA in the reaction tube. You find the
following:
Immediately after which of the following processes of PCR did the thermocycler break down?
A.
B.
C.
D.
DNA melts
topoisomerase uncoils the DNA
DNA polymerase elongates the strand
primase adds a new primer
E.
F.
G.
H.
annealing occurs
helicase breaks hydrogen bonds
ligase joins the Okazaki fragments
Taq polymerase elongates the strand
Biology 200, Autumn 2014
Problem Set Week 11
15.You are a forensic scientist, examining DNA evidence for a murder trial. You are trying to
determine from a list of 5 suspects who could have been the perpetrator of this heinous
crime. You take DNA samples from the 5 suspects (labeled A-E), the murder victim (V) and
some blood found underneath the victim’s fingernails (F). Below are gels showing the PCR
alleles from 2 different genetic loci. The “M” lane is for DNA marker.
A
B
C
D
E
V
F
M
A
B
Locus 1
C
D
E
V
F
M
Locus 2
a) Which locus is more useful for determining innocence of the suspects? Why?
b) Which of the suspects is most likely the murderer?
c) Is this enough evidence that you could convict this individual, with nothing else?
16. Each of the following is caused by meiotic nondisjunction:
a. Turner’s syndrome (XO female)
b. Down’s syndrome (Trisomy 21)
c. Klinefelter’s syndrome (XXY male)
d. XYY syndrome
For three of these syndromes, it is difficult to tell whether the nondisjunction occurred in the
mother or in the father. For one, it is clear. Which syndrome is it? In whose meiosis did it
occur? In which division? Explain how the other three karyotypes fail to reveal the source of
the nondisjunction.
17. Down’s syndrome men and women are able to mate and have offspring, although it is rare.
What chromosomal constitutions might be expected in the zygotes of a mating between two
people with Down’s, and what would become of each of these types of zygotes?
Biology 200, Autumn 2014
Problem Set Week 11
18. In a wonderful book entitled "Cats Are Not Peas", the author explores the genetics of her
male calico cat. How did this male come to be colored as such?
FROM THE TEXT: (Freeman 5e)
Ch. 13: 15
Ch. 14: 17, 23, 26
Ch. 20: 4, 6, 8, 10, 12, 16
FROM THE TEXT: (Freeman 4e)
Ch. 12: Test Your Understanding 6; Applying Concepts 3
Ch. 13: Genetics Problems 11, 14
Ch. 19: Test Your Knowledge 4, 6; Test Your Understanding 4, 6; Applying Concepts 4