Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Exam 1 GENE/BIOL 3000 Student ID# 810________________ Please write your full name on the back of the final page. This exam has 6 sets of problems, on 6 pages. Pay close attention to point totals in allocating your time. NO CALCULATORS. If you aren’t comfortable with the math, show your work as intended so we know what you were trying to do, or explain the concept verbally. Please answer the questions as succinctly as possible but write as legibly as possible. We will not grade the back of the pages, so limit your answers to the space provided. Use PEN ONLY; we will not regrade any exams written in pencil. 1. Using illustration and/or short answers, explain the four postulates underlying Darwin’s theory of natural selection. LABEL ANY DRAWINGS CLEARLY! (3 points each, total of 12 points) 1 2. Short Answer problems, use the space provided A. Looking at wild populations of finches, you measure beak depth of the parents at each nest, tag all of the offspring that hatch from that nest, and measure beak depth of the offspring from each nest the following year when they are fully grown. You do this twice and find the relationship shown in the graph at right. Explain TWO other factors that must be considered before determining whether this trait is heritable (4 points). B. Two species of shrimp differ at a fraction 0.07 of the nucleotides in a particular mitochondrial gene. One is found in the Caribbean, one in the Pacific, and a separate analysis suggests that they are each others closest relatives. If the Panamanian Isthmus arose 3.5 million years ago, what is the mutation rate at this gene (6 points)? 2 3. True or False? Circle the correct answer (2 points each, 12 points total) A. Natural selection influences the survival of individuals but populations change and evolve over time TRUE FALSE B. Cicada wings and bird wings are homologous TRUE FALSE C. At a single locus with two alleles, an individual homozygous for allele A1 produces white flowers, while either heterozygotes or homozygotes for allele A2 produce blue flowers. This is an example of additive genetic variation TRUE FALSE D. Phenotypic variation in a population is caused by both environmental and genetic factors TRUE FALSE E. Humans have selected for marine fishes to grow more slowly TRUE FALSE F. UGA is both a university and a stop codon TRUE FALSE 4. Provide one-sentence definitions for the following words, but be thorough (3 points each, total of 18 points) A. heterozygosity B. homology 3 C. paralog D. transversion E. irreducible complexity F. life history 5. Short Answer problems, use the space provided A. In the case of the major histocompatibility complex (MHC) in the human genome as discussed in class, what are two ways that Hardy-Weinberg equilibrium is violated (4 points)? B. In a standard deck of 52 cards, there are 4 equally represented “suits”: spades, clubs, hearts, diamonds. If I ask you to “pick a card, any card” what is the probability you pick a diamond? (2 points) When your friend is asked to do the same, what is the probability that BOTH OF YOU have picked a diamond card? (2 points) 4 5B continued: What is the overall probability, before either of you pick a card, that the two of you will have picked cards of different suits? (4 points) Explain how these questions are pertinent to evolutionary biology (4 points). C. Why is population size important for evolution, and derive a mathematical description of this important role (6 points) D. Explain why we think most mutations are deleterious. First, what type of experiment has been used to evaluate this hypothesis? (2 points) What is the primary difference between control and experimental conditions in this experiment? (3 points) What is the typical outcome of these experiments? (3 points) 5 6. Multiple Choice (3 points each, 18 points total) A. Kermode bears (white individuals of Ursus americanus) are thought to: 1. 2. 3. 4. be the result of hybridization with polar bears have a competitive advantage with dark-furred bears when fishing have originated during the Oligocene both 1 and 2 are true B. We learned about reverse transcriptase in the HIV genome because: 1. 2. 3. 4. RNA is damaged by this protein, preventing infection some variants are less likely to mistake AZT for thymidine this enzyme requires special nucleotides such as AZT for synthesis This is responsible for the disease in contemporary banana populations C. Selection coefficient: 1. Ranges from 0 to 1 2. Represents the proportional difference in reproduction or survival between genotypes 3. Depends on the environment in which it is tested 4. Only meaningful for heritable traits 5. All of the above D. Polyploidy is a result of: 1. 2. 3. 4. transversion speciation genome duplication decreased fitness E. Not a condition for Hardy-Weinberg equilibrium to be met: 1. 2. 3. 4. no mutation effectively infinite population size allelic variation random mating F. Alleles that are homozygous lethal persist because of: 1. 2. 3. 4. orthology Small fitness consequences synonymous mutations in coding regions when rare they are usually in heterozygotes 6