Ecosystems MCQs

Tech Books Yard have 70 Ecosystems for Free Download

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