Ecosystems MCQs
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Epitaxial growth is used in ICs
- A. because it produces low parasitic capacitance
- B. because it yields back to back isolating pn Junction
- C. to grow single crystal n doped silicon on a single crystal P-type substrate
- D. to grow Selectivity single crystal P doped silicon of one resistivity on a P type substrate of a different resistivity
- Correct Answer: Option D
The main cause of the increase in the amount of CO 2 in Earthʹs atmosphere over the past 150 years is
- A. increased worldwide primary production.
- B. increased worldwide standing crop.
- C. an increase in the amount of infrared radiation absorbed by the atmosphere.
- D. the burning of larger amounts of wood and fossil fuels.
- Correct Answer: Option D
Which of the following is a consequence of biological magnification?
- A. Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers.
- B. Populations of top-level predators are generally smaller than populations of primary consumers.
- C. The biomass of producers in an ecosystem is generally higher than the biomass of primary consumers.
- D. Only a small portion of the energy captured by producers is transferred to consumers
- Correct Answer: Option A
The Hubbard Brook watershed deforestation experiment yielded all of the following results except that
- A. the flow of minerals out of a natural watershed was offset by minerals flowing in.
- B. deforestation increased water runoff.
- C. the nitrate concentration in waters draining the deforested area became dangerously high.
- D. calcium levels remained high in the soil of deforested areas.
- Correct Answer: Option D
Which of the following has the greatest effect on the rate of chemical cycling in an ecosystem?
- A. the ecosystemʹs rate of primary production
- B. the production efficiency of the ecosystemʹs consumers
- C. the rate of decomposition in the ecosystem
- D. the trophic efficiency of the ecosystem
- Correct Answer: Option C
Nitrifying bacteria participate in the nitrogen cycle mainly by
- A. converting nitrogen gas to ammonia.
- B. releasing ammonium from organic compounds, thus returning it to the soil.
- C. converting ammonia to nitrogen gas, which returns to the atmosphere.
- D. converting ammonium to nitrate, which plants absorb.
- Correct Answer: Option D
Which of these ecosystems has the lowest net primary production per square meter?
- A. a salt marsh
- B. an open ocean
- C. a coral reef
- D. a grassland
- Correct Answer: Option B
Which of the following organisms is incorrectly paired with its trophic level?
- A. cyanobacterium--primary producer
- B. grasshopper--primary consumer
- C. zooplankton--primary producer
- D. eagle--tertiary consumer
- Correct Answer: Option C
Why are ecologists concerned about the shift in date from May 28 in 1980 to May 15 in 2000 of the caterpillar peak mass?
- A. The caterpillars will eat much of the foliage of the trees where flycatchers nest, and their nests will be more open to predation.
- B. The earlier hatching of caterpillars will compete with other insect larval forms on which the flycatchers also feed their young.
- C. The flycatcher nestlings in 2000 will miss the peak mass of caterpillars and may not be as well fed.
- D. The flycatchers will have to migrate sooner to match their brood-rearing season with the time of caterpillar peak mass.
- Correct Answer: Option C
The most likely cause for the shift in caterpillar peak mass is
- A. pesticide use.
- B. earlier migration returns of flycatchers.
- C. an innate change of biological clock by caterpillars.
- D. global warming.
- Correct Answer: Option D