Biology 1M03 Final Exam Questions Correctly Answered

Biology 1M03 Final Exam Questions Correctly Answered Interpret this statement: Extinct fossil species are typically succeeded by similar living species - Extinct and living forms represent ancestors and descendants Which is an example of developmental homology a) gene content b) similar organismal structures c)vestigial traits d) similar embryonic traits - d) Which is not one of Darwin's 4 Postulates: a) Individuals in a population vary in their traits b) These differences are not heritable; they are not passed onto offspring c) In each generation, many more offspring are produced than can survive d) Individuals with certain heritable traits are more likely to survive and reproduce - b) Explanation: These differences ARE heritable and ARE passed onto offspring Evolution by natural selection occurs when... - heritable variation leads to differential reproductive success Individuals with certain heritable traits are more likely to survive and reproduce. Is this statement true? - Yes Which of the following are evidence for evolution? (many may apply) i) Fossils ii)Vestigial traits iii)Transitional Forms iv)Non-transitional forms - i), ii), iii) The bacterium Mycobacterium tuberculosis causes tuberculosis (TB) Rifampin is an antibiotic used as treatment DNA from rifampin-resistant bacteria has a single point mutation in the rpoB gene Rifampin works by interfering with bacterial RNA polymerase, but the mutation prevents this During antibiotic therapy with rifampin, bacteria cells with normal RNA polymerase grow more slowly or die, but those with mutant RNA polymerase proliferate. Did natural selection occur? What happened? - Natural selection occurred and allowed for the survival and reproduction of antibiotic-resistant bacteria Is this statement true or false: Evolution is goal directed - False, evolution is not goal directed Which is not an example of a fitness trade off? a) Brain size b)Parental Care c)Sickle cell anemia d)Pleiotropic effects e) None of the above, they are all examples - e) What are the assumptions of Hardy-Weinberg equilibrium? a) Natural selection, genetic drift, gene flow, mutation, biased mating b)No Natural selection, No genetic drift, No gene flow, No mutation, No biases mating - b) How does natural selection affect genetic variation? a) can lead to maintenance, increase or reduction of genetic variation b) Reduces genetic variation c)May increase genetic variation by introducing more alleles; may decrease it by removing alleles d)Increases genetic variation e)No change - a) Explanation: b) is genetic drift c) gene flow d) mutation e) biased mating Which is not a type of natural selection? a) Directional Selection b)Depressional Selection c) Disruptive selection d) Balancing selection - b) When fitness is highest in rare phenotypes, it is characterized as: a) Negative frequency dependent selection b) Positive frequency dependent selection - a) Explanation: b) fitness is highest in COMMON phenotypes Which is a pattern of natural selection a) Heterozygotes typically have higher fitness than homozygotes b) Homozygotes have higher fitness than heterozygotes c)There is no correlation between fitness and homozygotes and heterozygotes - a) Which is true about Balancing selection a) Favours one extreme phenotype b)Genetic Variation is reduced c)Genetic variation is maintained d)None of the above - c) Which type of natural selection increases the frequency of one extreme phenotype? - Directional Selection Human babies of average size are most likely to survive Which type of natural selection does this represent? - Stabilizing Selection Which is false about genetic drift a)Causes genetic variation to decrease b)More pronounced in small populations c) Biased with respect to fitness d)Over time can lead to random loss or fixation of alleles - c) Explanation: Unbiased w.r.t. fitness Which is true about genetic drift, founder effects and bottlenecks a) Increase in number of alleles and an (maybe) increase in frequency b)Increase in number of alleles and (maybe) decrease in frequency c) Decrease in number of alleles and (maybe) increase in frequency d) Decrease in number of alleles and (maybe) decrease in frequency - c) True or False: Biased mating (inbreeding or sexual selection) violates H-W equilibrium. - True Inbreeding depression is best described as... a) Decline in average fitness when homozygosity decreases and heterozygosity increases b) Decline in average fitness when homozygosity increases and heterozygosity decrease c) Decline in average fitness when homozygosity and heterozygosity are equal d)Incline in average fitness - b) How does Mutation effect genetic variation and average fitness a) increases genetic variation, random w.r.t. fitness b) increases genetic variation, decreases w.r.t. fitness c)decrease genetic variation, increase w.r.t fitness d) decreases genetic variation, decreases w.r.t. fitness - a), possibly b)- most alleles lower fitness Explanation : Mutation produces more alleles, these alleles can be advantageous to fitness or be disadvantageous What are the consequences of Sexual Selection? a) Fundamental Asymmetry of Sex b)H-W equilibrium c)Sexual dimorphism d) Sexual conflict e) b and c f) c and d - f) c and d What happens to a species if gene flow stops - Natural selection, genetic drift and mutation begin to act on the population independently Which describes the Biological Species Concept a) Species are distinguished by differences in size, shape or other morphological features b) based on reconstructing evolutionary history of populations c)Assigns individuals to the same species if they "actually or potentially interbreed" - c) What is the problem with the phylogenetic species concept a) may end up over diagnosing species b) can't be applied to any type of population c)Hard to apply to natural system d) Very subjective - a) Explanation: b) It can be applied to every population c) Problem with Biological species concept d)Problem with morphospecies concept What is an advantage of the biological species concept a)There aren't any b)They can be applied to any type of population c)It is very subjective d)It includes asexual organisms - a) Physical isolation occurs by... a) Dispersal b) Vicariance c) Both d) Neither - c)