Ecology Test

Team Name ………………………………………………….

Team Number ……….

Student Names …….………………….……………………..

Science OlympiadFairfax HS Invitational

January 20171

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ECOLOGY TEST

I. GENERAL ECOLOGY SECTION – 30 pts – Please answer in the answer sheet provided

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1) Which of the graphs illustrates the population growth curve of a single bacterium growing in a flask of ideal medium at optimum temperature over a 24-hour period?

2) Which of the graphs illustrates the growth curve of a small population of rodents that has grown to reach a static carrying capacity?

3) Which of the graphs illustrates the growth over several seasons of a population of snowshoe hares that were introduced to an appropriate habitat also inhabited by predators in northern Canada?

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Use the following diagrams depicting the age structure of three populations to answer questions 4 - 7.

4) Which population(s) appear(s) to be stable?

5) Assuming these age-structure diagrams describe human populations, in which population is unemployment likely to be a societal issue in the future?

6) Assuming these age-structure diagrams describe human populations, which population(s) is (are) likely to experience zero population growth (ZPG)?

7) Which population(s) is (are) in the process of decreasing?---------------------------------------------------------------------------------------------------------------------------------------------------------

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Use the following diagram of five islands formed at around the same time near a particular mainland, as well as MacArthur and Wilson's island biogeography principles, to answer questions 8-10.

8) Which island would likely have the greatest species diversity?

9) Which island would likely exhibit the most impoverished species diversity?

10) Which island would likely have the lowest extinction rate?

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Use the survivorship curves in this figure to answer questions 11-14.

11) Which curve best describes survivorship in elephants?

12) Which curve best describes survivorship in a marine crustacean that molts?

13) Which curve best describes survivorship in humans?

14) Which curve best describes survivorship in marine molluscs?

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Use the following diagram of a hypothetical food web to answer questions 15-17.The arrows represent the transfer of food energy between the various trophic levels.

15) Which letter represents an organism that could be a producer?

16) Which letter represents an organism that is exclusively a herbivore?

17) Which letter represents an organism that is exclusively a carnivore?

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Questions 18-20 refer to this diagram of the nitrogen cycle.Which letter shows the following:

18) Assimilation of nitrate by photosynthetic eukaryotes

19) Nitrogen fixation by prokaryotes

20) Denitrification by anaerobic prokaryotes

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21) According to the Shannon Diversity Index, which block would show the greatest diversity?

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Researchers in the Netherlands studied the effects of parental care given in European kestrels over five years. The researchers transferred chicks among nests to produce reduced broods (three or four chicks), normal broods (five or six chicks), and enlarged broods (seven or eight chicks). They then measured the percentage of male and female parent birds that survived the following winter. (Both males and females provide care for chicks.)

22) Which of the following is a conclusion that can be drawn from this graph?A) Both males and females had increases in daily hunting with the enlarged brood size.B) Male survivability decreased by 50% between reduced and enlarged brood treatments.C) Chicks in reduced brood treatment received more food, weight gain, and reduced mortality.D) Female survivability is more negatively affected by larger brood size than is male survivability.E) There appears to be a negative correlation between brood enlargements and parental survival.

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23) A culture of Elodea is maintained in an experimental water solution containing dissolved carbon dioxide and a source of phosphates but lacking nitrogen compounds. A researcher determines the rates of synthesis of several organic compounds found in the Elodea before and after several weeks in the experimental water solution.Which of the following graphs best illustrates a likely result of the experiment?

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24) Assume there are 50,000 joules (J) of energy available in trophic level II in the figure.According to the conventional model of energy flow in ecosystems, which of the following statements correctly describes the flow of energy in the system?

A. Trophic level I generates a maximum of 50,000 J of energy.B. Trophic level I has approximately 5,000 J of available energy.C. Trophic level III has approximately 50 J of available energy.D. Trophic level IV has approximately 500 J of available energy.

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25) Scientist often cannot count all the individuals in a population. To estimate the size of an animal population, researchers often use a method known as mark-recapture, which involves marking individuals from a large population for easy identification upon recapture. The mark-recapture method assumes that the proportion of marked individuals in the recapture group is equal to the proportion of marked individuals in the entire population.To measure the population of lake trout in a 250-hectare lake, 400 individual trout were netted and marked with a fin clip, then returned to the lake. The next week, the lake was netted again, and out of the 200 lake trout that were caught, 50 had fin clips. Using the capture-recapture estimate, the lake trout population size could be closest to which of the following?

26) Approximately how many kg of carnivore biomass can be supported by a field plot containing 1,000 kg of plant material?

27) Secondary consumers that can eat only primary consumers receive what percent of the energy fixed by primary producers in a typical field ecosystem?

28-29) (2 pts) A porcupine eats 3,000 J of plant material. Of this, 2,100 J is indigestible and is eliminated as feces, 800 J are used in cellular respiration, and 100 J are used for growth and reproduction. What is the approximate production efficiency of this animal?

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30) How much carbon (in g/m2) is released into the atmosphere as a result of the metabolic activity of herbivores?

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II. BIOMES SECTION: Tundra, Taiga (Boreal Forest), Deciduous Forest (Temperate Forest)

30 pts – Please answer in the answer sheet provided-----------------------------------------------------------------------------------------------------------------------------------------------------Use the following graphs to answer questions 31-33.

31) In which biome would you expect to find in an area with an average temperature of 10o C and 100 cm of precipitation annually?

32) In which biome would you expect to find the lowest temperatures?

33) Which biome is characterized by rich soils and abundant decomposers - Tundra, Taiga or Temperate Forest?

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34) In this climograph during the months of February and March plant growth is more constrained by ____________ than by ____________.

a. sunlight; temperatureb. precipitation; temperaturec. temperature; sunlightd. temperature; precipitatione. stream flow; precipitation

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35) Which biome is characterized by the presence of permafrost?

36) Boreal forests (taiga) tend to have a thick layer of organic material but the soil is poor in nutrients. What is the best explanation for this?

a. The organic material is low in nutrients.b. The rapid growth rate of plants uses the nutrients rapidly.c. The soils have a low permeability and the nutrients do not dissolve in the soils.d. The soil is too rocky to hold a high content of nutrients.e. Low precipitation rates and cold temperatures slow decomposition.

37) If global warming continues at its present rate, regions that are now taiga will be replaced by ________________?a. tundra and polar iceb. temperate broadleaf forest and grasslandc. desert and chaparrald. chaparral and temperate broadleaf forest

38) What is the limiting factor for the growth of trees in the tundra?

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a. pH of soilsb. low precipitationc. permafrostd. cold temperaturese. insufficient minerals in bedrock

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The eight climographs below show yearly temperature (line graph and left vertical axis) and precipitation (bar graph and right vertical axis) averages for each month for some locations on Earth. Choose the climograph that best answers the question or completes the statement. Climographs may be used once, more than once, or not at all.

39) Which climograph shows the climate for Alaska, location 1? Choices: A C E G

40) Which climograph shows the climate for the South East USA, location 5? Choices: A C D E

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41) The biological community that characterizes the arctic tundra is:a. migrating herbivores, small mammals, and predatory birds.b. large trees.c. mosses, lichens, and dwarf woody plants.d. diverse amphibians and reptiles.e. A and C

42) Soils of the tundra are very ________ due to ______ .a. old; lack of precipitationb. young; lack of precipitationc. old; glaciationd. young; glaciation

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Answer the following questions in reference to these biomes:A. TundraB. TaigaC. Deciduous forest

Which biome is most likely to have …

43) large populations of short plants adapted to strong winds.

44) a population of moose.

45) plants that are flexible and grow close together.

46) plants that reproduce asexually because of the short growth season.

47) plants such as spruce and fir.

48) animals that mate and raise their offspring in a very short period of time.

49) plants with thick bark and waxy cuticles.

50) populations of deer and squirrels.

51) animals that grow extra fur on the bottom of their feet to move through snow more easily.

52) broad leaved-trees such as oak and maple.

53) a shrub layer composed of rhododendrons, azaleas and mountain laurels.

54) plants that carry out photosynthesis at low temperatures and low light intensities.

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55-56) (2 pts) This diagram shows the energy flow in a deciduous forest (kJ/m 2). How much energy is contained in the shrub layer?

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Use the following information to answer questions 57-60.

The Alaskan National Wildlife Refuge (ANWR) on Alaska’s North Slope is frequently in the news because petroleum geologists estimate that there are billions of barrels of economically recoverable oil beneath the surface of its frozen tundra. According to a 1998 United States Geological Survey (USGS) estimate, ANWR could contain up to 10 billion barrels of technically recoverable oil. Oil company officials advocate opening the refuge to oil exploration and the subsequent development of its petroleum resources. Environmentalists argue that oil exploration and development will damage this fragile ecosystem and urge Congress to protect ANWR by designating it as a wilderness area.

57-58) (2 pts) The United States consumes approximately 20 million barrels of oil per day.According to the USGS estimate, for how many days would the technically recoverable oil resource in ANWR supply the total United States demand for oil?

59-60) (2 pts) Give TWO characteristics of arctic tundra that make it a fragile environment.III. HUMAN IMPACT SECTION – 30 pts – Please answer in the answer sheet provided

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61) This causes an increase in the intensity of UV radiation reaching Earth.a. greenhouse effectb. depletion of ozone layerc. biological magnificationd. acid precipitation

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62) Based on the concept of ecosystem stability and the information provided in the graph, which community (A-E) would likely support the most biodiversity?

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Questions 63 - 66.

Flycatcher birds that migrate from Africa to Europe feed their nestlings a diet that is almost exclusively moth caterpillars. The graph shows the mean dates of arrival, bird hatching, and peak caterpillar season for the years 1980 and 2000.

63) What is the dependent variable in these graphs?

64) What is the independent variable in these graphs?

65) The shift in the peak of caterpillar season is most likely due toa. acid precipitation in Europe.b. global warming.c. pesticide use.d. earlier migration returns of flycatchers.

66) Why were ecologists concerned about the shift in the peak caterpillar season from June 3, 1980, to May 15, 2000?

a. The 2000 flycatcher nestlings would miss the peak caterpillar season and might not be as well fed.

b. The earlier hatching of caterpillars would compete with other insect larval forms which the flycatchers would also use to feed their young.

c. Pesticides, which have a negative effect on the ecosystem, would have to be used to control the earlier outbreak of caterpillar hatching.

d. The flycatchers would have to migrate sooner to match their brood-rearing to the time of peak caterpillar season.

Questions 67-69

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Match these terms with the appropriate term/phrase given.A. biological magnificationB. acid precipitationC. greenhouse effectD. depletion of ozone layerE. eutrophication

67) This term refers to the reflecting and absorption of infrared radiation by atmospheric methane, carbon dioxide, and water.

68) This is caused by excessive nutrient runoff into aquatic ecosystems.

69) This causes extremely high levels of toxic chemicals in fish-eating birds.

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Questions 70-75

Between 1950 and 2000, global meat production increased from 52 billion kilograms to 240 billion kilograms.During this period, the global human population increased from 2.6 billion to 6.0 billion.

70-71) Calculate the per capita meat production in 1950 and in 2000.

72-73) Why it is more efficient to produce grain for human consumption than to produce meat for human consumption.

74-75) Give TWO environmental consequences of the increase in the production of meat for human consumption.

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Use this diagram about the greenhouse effect for questions 76-80

Identify what the following numbers in the figure represent76) #2 is a molecule of ______________77) #3______________78) #4 is a molecule of ______________

79) Global warming/climate change results from an increase in which molecule found in this diagram? (name the molecule)

80) Which of the following actions are not related to the increase or buildup of greenhouse gases?

a. plant a tree or, better yet plant many treesb. use your automobile less, and ride a bicycle morec. produce less waste that goes to landfillsd. be certain your air conditioner uses chlorofluorocarbons.e. be certain your next automobile is more fuel-efficient

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81) Stratospheric ozone is important, as it:a. traps reradiated heat from the earth.b. prevents heat penetration from the sun.c. replenishes the surface ozone layer.d. dissipates the surface ozone layer.e. blocks solar UV radiation.

82) What compound is responsible for most of the damage done to the ozone layer?

83) What type of carcinogenic radiation has increased as a direct result of stratospheric ozone depletion?

84) What type of cancer is commonly associated with ozone depletion?

Questions 85-90

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According to atmospheric temperature and CO2 concentration records derived from Antarctic ice cores, Earth’s climate has undergone significant changes over the past 200,000 years.Two graphs are shown below. The upper graph shows the variation in atmospheric CO2 concentration, and the lower graph shows the variation in air temperature. Both graphs cover the same time period from approximately 200,000 years ago up until the year 1950, which is represented as year 0 on the graphs.

85) Determine the net change in atmospheric CO2 concentration between 140,000 years ago and 125,000 years ago.

86) Determine the net change in temperature between 140,000 years ago and 125,000 years ago.

87-88) Calculate the ratio of the change in mean global temperature to the change in atmospheric CO2 concentration between 140,000 years ago and 125,000 years ago.

89-90) Scientists predict that between 1950 and 2050, the atmospheric CO2 concentration will increase by 200 ppm.Predict the change in mean global temperature between 1950 and 2050 using the ratio that you calculated in the previous question).

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