1510 Biology Fall 2007: Exam 2 (version 1) General Instructions: Read these instructions. Do not open this exam until instructed to do so. Note the version of this exam, which is shown in the header to each page. Bubble in the version number in Column P under "Special Codes". If you do this incorrectly, your exam will not be graded with the correct key, which will likely result in a very poor grade. Completely fill in your name and 9-digit GT ID number (9xxxxxxxx) on the left side of the exam sheet. Start entering your ID number from the first column on the left and leave the last column blank. Your ID number is critical in entering your score into the class database. Any errors in your name and/or ID entries will result in 5 points being subtracted from your final score! This is not a joke! Write your lab section ID in the top right corner of your scantron sheet. This exam contains 42 questions, each worth 2.5 points. You can score a maximum of 100 points on this exam, so you can potentially attain the maximum score even if you skip or miss 2 questions. Please look over the entire exam before starting to work on any part of it. Please make sure that your copy of the exam includes all 10 pages of questions. Write your name at the bottom of each exam page. Please think through each answer carefully. None of these are intended to be trick questions, so try to answer only the question asked. Choose the best answer among the choices given. Turn in both the question sheets and the answer sheet. You must show your student ID and tell us your lab section (day & time) when you turn in your exam. Please be prepared when you come up to the front of the class. Good luck!
Name: _______________________________
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Biology 1510 Fall 07: Exam 2 (version 1) 1. The connection between ecology and evolution is described by which of the following? A. scientists interested in ecology are often the same kind of people that are interested in evolution. B. Darwin and his peers were predominantly ecologists, and it was through their studies of ecology that evolution by natural selection was discovered. C. an organism's ecology sets the context for evolution by natural selection. D. they cover different realms of science and have very little overlap. E. none of the above. 2. On a global scale, the amount of rainfall various regions receive is highly variable. Which of the following mechanisms explains an aspect of this observation? A. Intense solar radiation at the equator causes the air mass over the equator to be very dry. B. Fairly weak solar radiation at the poles causes the water vapor in polar air masses to precipitate (here, as snow). C. Coriolis effects cause air masses to expand and absorb moisture from their surroundings. D. Adiabatic processes cause rising parcels of air to cool; when the air in a parcel reaches the dew point, water precipitates as rain. E. Dry winds blowing east to west over oceans along the equator absorb moisture, then precipitate it over land masses. 3. Which of the following best explains why the polar regions of Earth are cold? A. The angle of incidence for solar radiation is low at the poles. B. The Earth is tilted on its axis. C. Adiabatic cooling of air masses transports heat from the poles to the equator. D. The Earth's orbit around the sun is elliptical. E. The spin of the planet causes cold, deep water to be brought to the surface at the poles, transporting heat to the equator. explanation of revision for Q3: I'm an idiot I had this one bubbled in wrong on my key. 4. Which of the following mechanisms explains the phenomenon of "lake turnover"? A. When warming surface waters in spring and cooling surface waters in fall reach the same temperature and density as the deeper waters stratification breaks down and mixing occurs. B. Strong winds, associated with spring and fall storms, mix the otherwise stratified water-layers within a lake. C. As surface water temperatures approach 0C in late fall / early winter, this increasingly dense water layer sinks and is replaced with the somewhat warmer, less dense, water from the bottom of the lake. D. In summer, high levels of solar radiation result in high rates of photosynthesis by benthic plants. As the oxygen bubbles resulting from photosynthesis bubble to the surface, they mix the deep and shallow waters. E. None of the above.
Name: _______________________________
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Biology 1510 Fall 07: Exam 2 (version 1) 5. Which of the following figures does not provide evidence that behavioral phenotypes can be heritable? A. A selection experiment which found a correlation between parent phenotype and offspring phenotype. B. Instinctive, innate behaviors: for example, a gull nestling begging for food from its parents by pecking at the red spot on the parent's bill. C. Hybrid crosses between individuals of the same species, but from different populations with different behaviors, results in offspring that exhibit aspects of the behaviors of neither parent populations. D. Different individuals of the same species exhibit different behaviors. E. Hybrid crosses between individuals of different species, with different behaviors, results in offspring that exhibit aspects of the behaviors of both parent species. 6. The stereotypical attack pattern of a white shark spot prey, attack from behind and below, inflict a single devastating bite, move away until the prey stops moving is an example of... A. a sign stimulus attack B. a fixed action pattern C. a learned behavior D. a Tinbergen loop E. imprinting 7. Which of the following statements is (are) true of fixed action patterns? A. They are genetic in basis. B. They are triggered by sign stimuli in the environment and, once begun, are continued through to completion. C. An inappropriate stimulus can sometimes trigger them. D. A and B only E. A, B, and C 8. Given the following information, at what search time is the predator predicted to generalize? Food item #1: E1=12, h1=2; Food item #2: E2=24, h2=2 A. s1=0; s2=0 B. s1=2; s2=0.5 C. s1=0; s2=1 D. s1=1; s2=1 E. s1=2; s2=3
Name: _______________________________
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Biology 1510 Fall 07: Exam 2 (version 1) 9. Which of the following statements concerning the evolution of behavior is correct? A. Natural selection will favor behaviors that enhance survival and reproduction. B. An animal may show behavior that maximizes reproductive fitness. C. Natural selection cannot affect the evolution of behavior because there is no genetic variance for behavioral characters. D. A and B only E. A, B, and C 10. Choose the best answer to complete this statement: A population will not reach equilibrium if: A. Birth rates are density-independent and death rates are density-independent. B. Birth rates are density-dependent and death rates are density-independent. C. Birth rates are density-independent and death rates are density-dependent. D. Birth rates are density-dependent and death rates are density-dependent. E. None of the above Use the following life table for a hypothetical cohort of organisms to answer questions 11-13. Age Interval (y) 01 12 23 34 45 5-6 Number alive at beginning 200 50 40 20 10 0 Number Dying 150 (?) 20 (?) 10 Death Rate 0.75 0.20 0.50 0.50 1.00 Number of Offspring per Individual 0 0 3 9 4
11. During which of the following age intervals does this organism have the highest risk of mortality? A. 0-1 B. 1-2 C. 2-3 D. 3-4 E. cannot tell from the information given 12. Which of the following statements is true? A. 10 individuals died in age interval 1-2. B. 20 individuals died in age interval 1-2. C. More individuals died in age interval 1-2 than in age interval 3-4 D. Individuals have the highest probability of dying during their second year of life E. None of the above is true
Name: _______________________________
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Biology 1510 Fall 07: Exam 2 (version 1) explanation of revision for Q12: I'm an idiot I had this one bubbled in wrong on my key. 13. From this life table, you can conclude that: A. on average, reproductive output is lower for age interval 34 than for the interval 45. B. individuals begin reproducing in their first year of life. C. reproductive output increases continuously with age. D. sexual maturity occurs at about 2 years of age. E. the oldest individuals have the highest reproductive output. 14. The growth rate of a population in with limited resources A is equal to (b d)N B. is greater than the intrinsic rate of increase C. is affected by interspecific competition for resources D. is less than the intrinsic rate of increase E. is described by a U-shaped curve. explanation of revision for Q14: resources are limiting, so the growth rate will always be less than the intrinsic rate of increase: r. During some of my lectures on pop growth, I defined r = (b - d); in words: if the birth rate is greater than the death rate, then the population will increase. Defining r in this way implies that b and d are density-independent. If b and d were densityindep, then answer A would have been wrong for the reason I gave above. However, at another point in my lectures, I also talked about how b ad d can themselves be functions of population density, so answer A would be correct as well. 15. Which of the following is true of the carrying capacity, which is often symbolized "K"? A. The rate of population growth in an unlimited environment is proportional to K. B. When N = K, the birth rate in a population is zero. C. In a population at its K, the birth rate equals the death rate. D. K is always determined by the amount of food in an environment. E. K, unlike other characters of a species, cannot evolve over time 16. Often the growth cycle of one population has an effect on the cycle of another - as hare populations increase, lynx populations also increase. Thus, if we are considering the logistic equation for the lynx population
dN
dt
rN (
(K K
N)
which of the factors accounts for the effect of the hare population? A. N B. rN C. r D. K E. dt 17. Fisheries biologists use the logistic equation to set the maximum take for a species at Name: _______________________________ p. 5 of 11
Biology 1510 Fall 07: Exam 2 (version 1) _______ because this maximizes the population's growth rate. A. r. B. K C. r D. K E. N 18. Which of the following is not an assumption of the logistic model for population growth? A. All individuals have the same effect on population growth B. There is no time lag between birth and the time an organism begins to affect population growth. C. Population growth rate increases as the size of the population approaches the carrying capacity. D. Members of the population compete for resources at high density. E. The environment imposes a carrying capacity on the population 19. A species that is relatively r-selected might have all of the following characteristics except A. small offspring B. numerous offspring C. high capacity for dispersion D. high investment long-term in tissues E. poor competitive ability 20. A single bacterium put in an environment with unlimited resources and no competition would... A. reproduce logistically towards infinity B. reproduce exponentially towards infinity C. reproduce linearly towards infinity D. Both A and C E. Both B and C 21. Communities can be linked by which of the following? I. predation II. systematics III. competition A. I only B. II only C. III only D. I and II E. I and III 22. If two species have completely overlapping niches, the competitive exclusion principle predicts... A. that all else equal the species with the greater reproductive rate will win (ie, drive the inferior species extinct) B. that all else equal the species that requires less resources per individual will win
Name: _______________________________
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Biology 1510 Fall 07: Exam 2 (version 1) C. that all else equal the species that initially attains a higher density than its competitor will win D. any two of the above answers E. all of the above explanation of revision for Q22: What I meant answer D to mean was "any combination of two of the above answers"... very confusing sorry. We wound up accepting all asnwers
23. Two species of barnacle, Balanus and Chthamalus, can both survive on the lower rocks just above the low-tide line on the Scottish coast, but only Balanus actually does so; Chthamalus adopts a higher zone. Which of the following best accounts for this niche separation A. Competitive exclusion. B. Predation of Chthamalus by Balanus. C. The starfish Pisaster preferentially preys on Chthamalus. D. Primary succession. E. The fundamental niche of Chthamalus does not extend below the low-tide line. 24. Which of the species in the example above have any chance of reaching K? A. The low intertidal Balanus. B. The high intertidal Chthamalus. C. The starfish Pisaster. D. The starfish's alternative prey Mytilus. E. None of the above. explanation of revision for Q24: welllll, Chathamalus in the high intertidal will be free of competition from Balanus, so they could reach K. But then Balanus down low are so competitively dominant to Chthamalus that they can reach K too. Not a great question.
25. A population such as Sweden's, which has a low birth rate and a low death rate, A. will have a population dominated by young individuals. B. will have a relatively even distribution of individuals of different ages C. will have a population dominated by old individuals. D. will have a population dominated by individuals of intermediate age, with relatively few young or old individuals. E. can have almost any age distribution. Birth and death rates do not affect the age distribution. 26. The presence of all of the following tend to increase species diversity except A. disturbance B. predation C. competition D. patchy environments E. mutualism 27. A species of fish is found to require a certain water temperature, a particular oxygen content
Name: _______________________________
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Biology 1510 Fall 07: Exam 2 (version 1) of the water, a particular depth, and a rocky substrate on the bottom to thrive. These requirements are part of its A. dimensional profile B. resource partition C. home base D. prime habitat E. ecological niche 28. As you study two closely related predatory insect species, the two-spot and the three-spot avenger beetles, you notice that each species seeks prey at dawn in areas without the other species. Where their ranges overlap, however, the two-spot avenger beetle hunts at night and the three-spot hunts in the morning. When you bring them into the laboratory, their offspring behave as their parents did. You have discovered an example of: A. Mutualism B. Character displacement C. Batesian mimicry D. Facultative commensalism E. Aposematic competition 29. Resource partitioning would be most likely to occur between A. allopatric populations of species with similar ecological niches B. allopatric populations of the same animal species C. sympatric populations of a predator and its prey D. sympatric populations of a flowering plant and its specialized insect pollinator E. sympatric populations of species with similar ecological niches 30. The species richness of a community refers to the A. number of food chains B. the biomass of the community C. the bioenergetics of the community D. number of different species E. relative numbers of individuals in each species 31. In recent years, sea otter populations have declined in an alarming manner in the Pacific Northwest. This decrease may be related to: A. An increase in their competitor: sea lions B. A decrease in their prey: sea urchins C. A decrease in their refuge: giant kelp forests D. An increase in predation on sea otters by killer whales E. An increase in disease transmission due to warming waters off the Aleutian penninsula 32. The term "keystone" refers to a species which... A. is the most successful predator in a given habitat. B. is the most successful competitor in a given habitat. C. is the most productive autotroph in a given habitat. D. has the most biomass within a given habitat.
Name: _______________________________
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Biology 1510 Fall 07: Exam 2 (version 1) E. exerts substantial control over the structure of the community. 33. Imagine a simple three level trophic system: of primary producers > herbivores > predators. Which of the following statements concerning the control of such a community's structure is false? A. A top-down community is controlled by predators. B. A bottom-up community is controlled by nutrients. C. Increasing the number of predators in a top-down community will decrease the biomass of primary producers. D. Increasing the biomass of primary producers in a bottom-up community will increase herbivores. E. Increasing the rate of primary production in a bottom-up community will increase predators. 34. Primary production is higher in zones of upwelling because: A. the water in these areas has a greater concentration of nutrients. B. surface water in these zones conducts nutrients poorly. C. nutrient levels are lower in these zones. D. light transmission through the water column is greatest in these zones. E. estuaries transport limiting nutrients from terrestrial habitats to marine habitats 35. Predator and prey densities can exhibit a number of patterns from stable coexistence (only rather small changes in density over time) to stable extinction to coupled oscillations. In an oscillating system such as the lynx and the hare, what drives the cycle? A. High lynx density leads to low densities of grouse the hare's main competitors leading to an increase in hare density. B. High hare density leads to high lynx density leads to low hare density leads to low lynx density leads to high hare density. C. Environmental effects, such as extremely cold winters, drive oscillations in grouse and hare populations, and this in turn sets up an oscillation in the lynx population. D. Limiting nutrients cycle as a function of global weather pattern (e.g., el nio), setting up a cycle in the primary producers; the cycle is then reflected in the next two trophic levels: the herbivores and the carnivores E. The observed lynx/hare cycles are not linked, but are an inevitable result of resource overexploitation by hunters and habitat reduction. 36. The niche is best defined as... A. the range of physical and environmental parameters that define the living requirementas and conditions for a species. B. the fundamental physical space and biogeographical habitat where we may find a species. C. the role a species plays in its environment. D. any two of the above E. none of the above 37. Which of the following statements regarding productivity is not true? A. Gross Primary Productivity (GPP) will always exceed Net Primary Productivity (NPP). B. NPP, in terms of either biomass or joules, is the measure of production which may be passed
Name: _______________________________
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Biology 1510 Fall 07: Exam 2 (version 1) up the food chain. C. The ecological efficiency of homeothermic (warm-blooded) organisms is less than that of heterothermic (cold-blooded organisms) D. Terrestrial productivity is largely a function of evapotranspiration rates (which is itself a function of solar inputs and water availability). E. Herbivorous species generally have higher trophic efficiencies than carnivorous species. 38. Which of the following statements about the biogeographical aspects of diversity is not correct? A. Species richness on an island reaches an equilibrium point when immigration equals extinction. B. Islands, for example the Galapagos and Hawaiian archipelagos, generally exhibit higher biodiversity than continental land masses because there in reduced competition for niche space on islands. C. The patterns of continental drift are important considerations in the study of the past and present distributions of species. D. The magnitude of photosynthesis is the factor that accounts for the major variations in species diversity over large areas of Earth. E. A species may be limited to a particular range because it never dispersed beyond that range, or it dispersed but failed to survive in other locations. 39. Iron-supplementation experiments on mid-ocean systems reveal... A. oceanic blue-green (cyanobacteria) algae are iron-limited B. oceanic green algae are nitrogen-limited C. oceanic green algae are iron-limited D. A and B only E. A, B, and C explanation of revision for Q39: based on a misunderstanding of some outside reading for my lectures on this subject and my using the term "green algae" to describe photosynthetic eukaryotes / unicellular phytoplankton other than cyanobacteria, this turned out to be a terrible question. There are lots of other unicellular phytoplankton (such as diatoms) that are responsible for primary productivity in the ocean, and the link between iron and primamry productivity by cyanobacteria is not a firm as I had understood. We wound up counting all answers.
40. What is the fundamental difference between matter and energy? A. Matter is used in ecosystems; energy is not. B. Matter can be converted into energy; energy cannot be converted into matter C. Energy can be converted into matter; matter cannot be converted into energy D. Energy is cycled through ecosystems; matter is not E. Matter is cycled through ecosystems; energy is not 41. The difference between net and gross primary productivity would likely be greatest for...
Name: _______________________________
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Biology 1510 Fall 07: Exam 2 (version 1) A. phytoplankton in the ocean. B. corn plants in a farmer's field. C. sphagnum moss in a bog. D. an oak tree in a forest. E. prairie grasses. 42. Which of these ecosystems has the highest net primary productivity per square meter? A. temperate forest B. tropical rain forest C. boreal forest D. open ocean E. savanna
Name: _______________________________
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