1 Biol 321 Spring 2011 Final Exam [90 points] NAME________________________________________ • REMEMBER: carefully inspect problems and pay attention to detail! • YOU ARE NOT ALLOWED TO USE CALCULATORS OR CELL PHONES DURING THIS EXAM or to send or receive signals of any kind • READ EACH QUESTION CAREFULLY BEFORE ANSWERING. This exam is divided into two sections: Section 1: 50 pts total. You must answer every question in this section Section 2: 12 pts total. You must answer one of two options Section 3: 28 pts total. You must answer two of four options Problems (pts.) Score Section 1 50 pts Problems 1-4 (12) Problems 5 &6 (14) Problem 7 & 8 (14) Problem 9 (10) Section 2 12 pts Option 1 or 2 Section 3 28 pts Option 1-4 (14) Option 1-4 (14) Total (90)2 Section 1 (50 pts.) 1. (4 pts.) It is estimated that SNPs are found in 0.1% of all the base pairs in the human genome. a. Translate the acronym SNP_____________________________________________________ b. How many total SNP sites would be found in a single copy of the human genome? Show your work, track units and circle your answer. No credit if no work or no units. 2. (3 pts.) The enzymatic components of the post-synthesis mismatch repair system are encoded by the mutator (mut) genes. Based on your understanding of how genes have been traditionally named, briefly explain this apparent contradiction. Be sure to indicate the wildtype function (generally) of these genes. 1-3 sentences using proper terminology. 3. (2 pts.) Which statement(s) is(are) false about the STR loci used for DNA fingerprints. a. They are under weak evolutionary constraints b. Different alleles show codominance c. They represent regions of the genome with scattered repeats due to transposable element duplication and movement d. They are inherited like any standard Mendelian allele e. They have a relatively high mutation frequency 4. (3 pts.) State and briefly explain one difference in the association mapping strategy used to identify the CCR5 polymorphism in HIV “resistant” individuals and the positional cloning strategy used to identify the “pain/no pain” gene. Three sentences maximum 5. (11pts.) Circle T or F for each statement. Answer false any part of the statement is false. If there are two statements, the first statement is true and you are to decide if the second statement is T or F. 1 pt if no explanation required. 2 pts if an explanation required. T F In the appropriate context, a loss-of-function allele may also be considered a polymorphism One sentence explanation3 T F By definition, a loss-of-function mutation can never be a neutral mutation. One sentence explanation: T F Excluding silent and neutral missense, most mutations in the proto-oncogene class of genes will result in driver alleles. One sentence explanation: T F The tumor suppressor class of genes (often found mutated in cancer cells) are named for their gain-of-function phenotype. T F Because of the the asexual nature of a cancer cell lineage, the number of passenger mutations can only increase in the descendants of a cancer cell lineage and never decrease. One sentence explanation: Recall the article GENOME DARK MATTER. By each statement circle True/False/subject Not addressed in this article. Answer false if any part of the statement is false. T F N Even though non-coding DNA is often considered junk DNA, vast stretches of this junk DNA are conserved between mice and men. T F N Although scientists expected to find 100,000 genes in the human genome the current count is between 40,000 and 50,000 genes per single copy. 6. (3 pts.) As species go, humans aren't renowned for their sense of smell. But an improved ability to suss out scents in our 200-million-year old ancestors may have laid the groundwork for the bulging brains of humans and all other mammals. Virtual three-dimensional 'casts' of the fossilized skulls of animals that preceded the first true mammals suggest that brain areas involved in smell, or olfaction, catalysed brain growth in the evolutionary branch that gave rise to mammals. The olfactory system was the thing that drove the expansion of the brain in the first place, and once you've got a big brain you can do all kinds of things with it," says Timothy Rowe, a palaeontologist . What did you learn in the chromosome 11 fly over that supports the statements in bold. Be explicit. 2-3 sentences.4 7. (8 pts.) A map of the Drosophila X chromosome is shown on the data sheet (pg 1). Check your work carefully before selecting your answer. Partial credit possible. (i) .(4 pts) A female of genotype m+ g / m g+ is crossed with a phenotypically wild-type male. All female progeny are wild-type. The percentage of male progeny that will have miniature wings and garnet eyes is: a. 4% b. 8 % c. 46% d. 92% e. 50% f. 100% g. not enough info to determine h. none of the above (ii) (2 pts) A female heterozygous for both the sable body and garnet eye genes is crossed with a phenotypically wild-type male. All female progeny are wild-type. The percentage of male progeny that will have both sable bodies and garnet eyes is: a. 0.5% b. 1 % c. 49.5% d. 99% e. 50% f. 100% g. not enough info to determine h. none of the above (iii) (2 pts) A female of genotype sc+ lf+/ sc lf is crossed with a phenotypically wild-type male. All female progeny are wild-type. The percentage of progeny males that will be wild type for both traits is: a. 0% b. 16 % c. 25% d. 34% e. 50% f. 68% g. not enough info to determine h. none of the above 8. (6 pts.) Page 3 of the DATA sheet shows data from a paper describing the positional cloning of a gene associated with microcephaly. True/False/Not enough Info to decide. Answer false if any part of the statement is false. If there are two statements the first statement is true and you are to decide if the second statement is true or false. Unless otherwise indiated, 2pts if explanation required; 1 pt if no explanation T F N These researchers used a positional cloning strategy to identify the specific gene that was mutated in this disease state. This suggests that from the very beginning of the project the researchers had a hunch as to what type of protein the gene coded for.