General Biology: BI101 Spring, 2007
STUDY QUESTIONS: Ch 41
1. The base of the energy pyramid represents ______.
a. producers b. decomposers c. primary consumers d. secondary consumers
e. tertiary consumers
2. Which of the following are heterotrophic?
a. producers b. decomposers c. primary consumers d. secondary consumers
e. The second, third, and fourth answers are all correct.
3. Of the following trophic levels, which would support the fewest organisms?
a. producer b. decomposer c. primary consumer d. secondary consumer
e. tertiary consumer
4. Which of the following trophic levels is always the final link in the food chain?
a. producer b. decomposer c. primary consumer d. secondary consumer
e. tertiary consumer
5. In the carbon cycle, carbon (C) is returned to the atmosphere by ______.
a. photosynthesis b. evaporation of water c. burning of fossil fuels
d. respiration of plants and animals e. The third and fourth answers are both correct.
6. For which of the following nutrients is rock a major reservoir?
a. water b. oxygen c. carbon d. nitrogen e. phosphorus
7. Which of the following is/are a major contributor to the problem of acid deposition?
a. oxygen b. carbon dioxide c. sulfur dioxide
d. nitrogen oxides e. Both the third and fourth answers are correct.
8. DDT and other substances that undergo biological magnification are dangerous because they are ______.
a. biodegradable b. not biodegradable c. fat soluble d. water soluble
e. Both the second and third answers are correct.
9. Which of the following nutrients remains chemically the same as it is cycled through the food chain and is generally not used in the synthesis of new molecules?
a. water b. carbon c. nitrogen d. phosphorus
e. Both the third and fourth answers are correct.
10. Which of the following materials cycle through an ecosystem: 1) carbon, 2) nitrogen, 3) oxygen, 4) water, and 5) energy?
a. 1 through 5 b. 1 through 4 c. 1 through 3 d. only 1 and 2 e. only 4 and 5
11. Although the textbook suggests that organisms remove nutrients from the reservoirs (where nutrients are stored), some biologists distinguish between the "reservoir," where nutrients are stored but not directly available to living organisms, and the "exchange pool," where nutrients are directly available, in usable form, to living organisms. For example, atmospheric carbon dioxide would be considered to be in the exchange pool for plants. Using this distinction, for plants, atmospheric nitrogen would be in the ______.
a. reservoir b. exchange pool c. biotic community d. all of the above
12. What term describes a photosynthetic alga?
a. producer b. autotroph c. consumer d. heterotroph
e. Either the first or second answer is correct. f. Either the third or fourth answer is correct.
13. A spider that feeds on an aphid that in turn feeds on germinating blades of wheat would belong to what consumer category?
a. herbivore
b. primary consumer
c. secondary consumer
d. tertiary consumer
14. What are macronutrients?
a. large molecules that provide a source of energy when ingested
b. molecules that are required in large quantities for an organism to survive
c. protein molecules
d. all of the above
15. How is nitrogen released back to the atmosphere once it has been incorporated into the body of an organism?
a. nitrogen fixation
b. through a process involving a symbiotic association with a legume
c. by decomposers and denitrifying bacteria
d. Both of the first two answers are correct.
16. Why is acid rain, or acid deposition, considered to be harmful?
a. Moisture in the air becomes acidified and then falls on plants and the soil below, harming them.
b. Acid rain leeches essential nutrients out of the soil (e.g., potassium and calcium), and kills decomposers in the soil.
c. Dead, or weakened, plants make the soil much more susceptible to erosion.
d. all of the above
17. Which of the following is NOT considered to be a greenhouse gas?
a. oxygen
b. water vapor
c. methane
d. carbon dioxide
18. Primary, secondary, and tertiary consumers are all names for different ______levels.
19. Organisms that eat the remnants of other living things, such as leaves, deceased animals, and other "litter," are called ______feeders.
20. The law that dictates how much energy passes between trophic levels (such as between primary consumers and secondary consumers) is called the ______law.
21. Cyanobacteria can turn the nitrogen in the atmosphere into a usable form for other organisms. This is called ______.
23. Bald eagle eggshells became dangerously brittle because the eagles had eaten fish from water polluted by the insecticide ______.
24. The image below indicates the different levels of productivity in the various ecosystems. Label these systems correctly.
Answer:
Label A: open ocean
Label B: estuary
Label C: tropical rain forest
Label D: tundra
Label E: continental shelf
Label F: coniferous forest
Label G: grassland
Label H: deciduous forest
Label I: desert
28. An ecologist studying a plot of ground in the tundra excludes all herbivores from her study area and estimates the plant biomass at 530 grams per square meter. She comes back to the same plot one year later and estimates that the biomass has increased to 670 grams per square meter. The difference in these two values, 140 grams, represents the ______for that year.
a. biological magnification b. food chain length c. food web complexity
d. net primary productivity e. trophic transfer efficiency
29. As one moves from the equator towards the poles, the net primary productivity of forest ecosystems generally ______.
a. decreases b. increases c. remains the same
d. first decreases and then increases e. first increases and then decreases
30. Conserving electricity by using fluorescent lights instead of incandescent lights and turning off lights and appliances when not in use ______.
a. actually increases greenhouse gas production as the predominant fossil fuel–powered electrical generating plants consume large quantities of carbon dioxide when they are operating
b. has no effect on greenhouse gas production because nearly all electricity in this country is produced by nuclear reactors and renewable wind and solar generating stations
c. helps reduce greenhouse gas production because the majority of electricity in this country is still produced by fossil fuel–powered generating plants. Since these plants produce carbon dioxide when they operate, conserving electricity reduces greenhouse gas production.
31. Of the solar energy that strikes the outer reaches of the Earth's atmosphere, approximately what percentage ends up in carbohydrate molecules produced by photosynthetic organisms?
a. 0.03% b. 1% c. 3% d. 10% e. 90%
32. Earthworms are ______.
a. detritus feeders b. herbivores c. primary consumers
d. producers e. secondary consumers
33. So far, global warming has been documented to be causing ______.
a. changes in precipitation patterns on land, with some areas subjected to more severe and frequent droughts, and other areas more frequent and severe floods
b. melting of ice sheets and retreat of glaciers at unprecedented rates
c. shifts in the distribution and abundance of a number of plant and animal species
d. shifts in the timing of spring events, which are occurring much earlier than previously
e. all of the above
34. Since the Clean Air Act Amendments of 1990 went into effect, acid precipitation has ______.
a. ceased to be a problem anywhere in the United States
b. declined somewhat in many areas but is still a problem, even continuing to get worse in some areas like the Adirondack Mountains of New York
c. continued on as before, unabated as the regulations are not being enforced
d. actually gotten much worse, as the controls were poorly planned and implemented and exacerbated the problem
3. In ecosystems, elements like carbon and nitrogen:
a. are neither created nor destroyed, but may change molecular form as they pass from organism to organism and between abiotic and biotic components.
b. are produced by the sun, travel to Earth, and pass briefly through ecosystems, being degraded in the process, and are ultimately lost to space.
c. play no role whatsoever.
1. The role of fungal and bacterial decomposers in the natural carbon cycle is to:
a. move carbon dioxide between the atmosphere and oceans.
b. release the carbon tied up in the tissues of dead organisms to the atmosphere in the form of CO2.
c. remove CO2 from the atmosphere and tie it up in the tissues of organisms.
2. How does using wood derived from trees as a source of fuel for cooking affect the carbon cycle?
a. It decreases the uptake of CO2 from the atmosphere as there are fewer trees carrying on photosynthesis.
b. It has no effect on the carbon cycle.
c. It increases the release of CO2 into the atmosphere as the wood is burned.
d. Both the first and third answers above are correct.
3. Over the last few decades, during which deforestation and the burning of fossil fuels have increased dramatically, global atmospheric CO2 concentrations have:
a. decreased significantly. b. increased significantly. c. remained about the same.
4. Increased levels of carbon dioxide and other greenhouse gases in the atmosphere contribute to global warming by:
a. allowing more sunlight to reach the Earth.
b. preventing more of the heat radiated from the Earth's surface from escaping into space.
c. promoting and sustaining forest fires and other forms of combustion that release heat.
1. An organism that makes its own food, i.e., "self-feeding," is said to be a(n):
a. consumer. b. heterotroph. c. autotroph. d. producer.
e. both C and D
2. What is the base of the food pyramid or the food chain in a marine ecosystem?
a. plankton b. zooplankton c. phytoplankton d. small fish
e. coral
3. Which of the following greenhouse gases does phytoplankton in the marine environment require for the process of photosynthesis, thereby assisting in the regulation of Earth's atmospheric composition?
a. oxygen b. hydrogen c. carbon monoxide d. carbon dioxide
e. sulfur dioxide
4. Organisms that eat dead or decaying material to gain their source of energy are called ______or ______.
a. autotrophs; consumers b. consumers; producers c. detritivores; herbivores
d. detritus feeders; decomposers e. decomposers; carnivores
5. Which trophic level has members that require uptake of ammonia, a complex form of nitrogen?
a. producers b. herbivores c. carnivores d. decomposers
1. Carnivores always consume:
a. other carnivores. b. herbivores only. c. producers only.
d. other animals, which could be herbivores, omnivores, or other carnivores.
e. dead things, so they are also detritus feeders.
2. Which of the following animals are omnivores?
a. deer b. wolves c. hyenas d. black bears e. fungi
3. What are the primary consumers of the ocean environment?
a. phytoplankton b. zooplankton c. small fish such as anchovies
d. big fish such as tuna e. jellyfish
4. If a pesticide such as DDT enters into a food chain, it may become concentrated in higher trophic levels. This is a concept best known as:
a. bioremediation b. toxification. c. accumulation. d. biodegradable.
e. biological magnification.
5. Which of the following organisms is considered to be exclusively a decomposer?
a. vultures b. bacteria c. worms d. fungi e. Both B and D.
6. Organisms that must rely on the complex high-energy molecules produced by other organisms for survival are:
a. heterotrophs. b. producers. c. autotrophs. d. cyanobacteria.
1. What makes the flow of energy through ecosystems fundamentally different from the flow of nutrients?
2. What is an autotroph? What trophic level does it occupy, and what is its importance in ecosystems?
3. Define primary productivity.
4. List the first three trophic levels. Among the consumers, which are most abundant? Why would you predict that there will be a greater biomass of plants than herbivores in any ecosystem? Relate your answer to the “10% law.”
6. Define detritus feeders and decomposers, and explain their importance in ecosystems.
Why is so much energy lost as heat? Explain this in terms of the second law of thermodynamics (introduced in Chapter 6) and relate it to the energy pyramid in Figure 41-7.
Why do temperatures rise in an actual greenhouse? Why is this a good analogy for heat-trapping by greenhouse gases?
1. What are the two underlying laws of ecosystem function?
2. Describe the differences between primary, secondary, and tertiary consumers.
3. Describe the 10% law and how it explains the ratio of primary consumers to secondary (or tertiary) consumers.
4. Explain why the largest nutrient reservoirs are typically found in the abiotic, or nonliving, parts of ecosystems.
6. Explain how a global temperature rise of 0.5 to 1.0 degrees C can have such a large effect on life on this planet.
7. Explain how the demise of the salmon population in a stream in the Pacific Northwest can impact the surrounding forest.
BI101SQ Ch41.doc 6 5/25/2007