December 14, 2011 Genetics BISC325, Final

26 Jun December 14, 2011 Genetics BISC325, Final

Question
December 14, 2011

Genetics BISC325, Final.

35 points total

Name___________________________ Student ID_____________________________

Your TA_________________________

Page 2 (6 points) _____

Page 3 (6 points)_____

Page 4 (6 points)_____

Page 5 (4 points)_____

Page 6 (4 points)_____

Page 7 (4 points + 2 bonus points)_____

PLEASE, don’t open your exam until permitted

PLEASE, use a non-erasable pen, or we will not be able to accept the exam for regrade

1. (2.5 points) A woman and her husband come to you for advice. A rare devastating X-linked recessive disease is segregating in the mother’s family. The gene that causes the disease is not known so the mother cannot be tested to see if she is a carrier. The couple desperately wants to have a child. What procedures could be used to guarantee that she will not have to terminate any pregnancies and will have a child that will not be affected by the disease?

Chapter 15.

2. (2 points). Briefly describe a life-style difference between viruses and transposable elements?

3. (1 point). What is the molecular biological evidence that the multiplication of retrovirus-like transposable elements involves reverse transcription?

4. (2 points). Briefly describe how the P-element system of hybrid incompatibility has been engineered to enable genetic transformation in flies.

5. (1 point). Briefly describe what is the contribution of transposable elements into the difference in the genome size among plant species.

Chapter 16.

6. (2 points). Name the types of single nucleotide mutations that might alter splicing.

7. (1 point). What is the typical (plus minus order of magnitude) mutation rate per nucleotide per generation (in humans or in flies or in any other organism)?

8. (2 points). Describe, briefly, how is Ames’ test used for revealing mutagenic compounds?

Chapter 17.

9. (1.5 points). Briefly describe why tetraploid species are much more common in nature than triploid species?

10. (1 pt.) Paracentric or pericentric inversions may lead to deficient gametes meiosis, but only if what molecular process takes place?

Chapter 18.

11. (1 pts.) In general, mammalian sperm are viable even if they are aneuploid, but pollen grains (a.k.a. “plant sperm”) are not. Why?

12. (1.5 pts.) In humans, roughly what percentage of conceptions give rise to healthy children without major chromosomal abnormalities? Why is this likely to be an overestimate?

13. (1.5 pts.) The frequency of brown oculocutaneous albinism, a phenotype caused by a recessive allele, is 1/1100 (=0.0009). Estimate the frequency of the recessive allele (you can simply write out the equation without solving it).

14. The following table shows the frequency of a particular SNP in a particular population:

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a. (1 pt) Briefly describe how expected numbers of each genotype were calculated.

b. (1 pts.) Name one population genetic process that could explain this deviation from Hardy-Weinberg equilibrium?

15. (2 pts.) Is random genetic drift strongest in small populations or large populations? Describe why.

16. (1 pt.) What is the initial frequency of a new mutation on a diploid chromosome?

(1 pt.) Assuming a equal number of breeding males and females, what is the initial frequency of a new mutation arising on the X chromosome?

(1 pt.) Assuming neutrality, what is the probability that a new mutation on a diploid chromosome reaches fixation?

(1 pt.) How might positive selection acting on the new mutation affect the probability that it reaches fixation?

Chapter 19

17. (1 pt.) Is this figure consistent with a model of additivity?

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(1 pt.) Briefly describe your answer.

18. (2 pts.) Define heritability, in words or equation. Why would a breeder of large tomatoes care about heritability?

19. (1.5 pts.) Describe one reason why whole genome association studies could lead to false positive results.

Chapter 20.

20. (1 pt.) Give one example of natural selection occuring via changes in protein sequence.

21. (1 pt.) Intuitively, why might evolution by natural selection be expected to proceed via changes in expression vs. changes in protein?