Week 5 Test Answers

Primary productivity is not limited by _______.a.the availability of sunlightb.timec.the availability of nutrientsd.access to water

All ecosystems are affected by wildfires equally.

Which of the following statements about prescribed burns is true?a.Prescribed burns will always have detrimental effects on ecosystems, but should be used to protect homes.b.Prescribed burns are necessary for preventing natural wildfires.c.Prescribed burns can help maintain healthy ecosystems.d.None of the above

Which statement best describes the relationship between photosynthesis and cellular respiration?

Which of the following is not an example of energy transformations in an ecosystem?a.sunlight driving photosynthesis in plantsb.herbivores feeding on plantsc.predators feeding on herbivoresd.none of the above

Where is the greatest amount of the world’s carbon found?

The carbon cycle ensures that carbon is not lost. Which is another important benefit of the carbon cycle?

Which of the following is true concerning the balance between the solar energy absorbed and radiated by Earth?a.Earth’s atmosphere absorbs a larger fraction of total solar energy than it radiates.b.More than 90% of the solar energy that strikes Earth is absorbed.c.Earth’s surface is responsible for absorbing a larger fraction of energy than it radiates.d.None of the above.

In what form is carbon found in the atmosphere?

Without wildfires, forest ecosystems would be more likely to suffer from outbreaks of plant disease.

Which of the following best describes the solar radiation absorbed by and radiated from earth?a.Most incoming solar energy is absorbed by the atmosphere.b.Only a small fraction of energy radiating from Earth is from the atmosphere.c.The Earth’s surface is responsible for a small fraction of heat radiation to space.d.Earth’s surface absorbs little of the energy that strikes as solar radiation.

Which of the following is true about the efficiency of energy transfer in an ecosystem?a.The more energy the organism requires, the more efficient the energy transfer.b.All energy transfers have the same efficiencies.c.The less energy the organism requires, the more efficient the energy transfer.d.The most efficient energy transfers are in large, warm-blooded animals.

Heterotrophs convert solar energy into chemical energy.

Prescribed burns are used to _______. a. clear out undergrowth b. prevent larger forest fires c. manage forests d. all of the above Please select the best answer from the choices provided

Which reason best explains why living things need carbon?

How will the level of carbon in the atmosphere change if humans do nothing to reduce their impact on the carbon cycle?

How does wildfire help restore soil nutrients?a.Wildfire kills off the soil organisms that consume soil nutrients.b.Wildfires restore soil nutrients by decreasing the amount of underbrush in forests that contribute to nutrient loss.c.Wildfires break down organic material faster than decomposition, thus renewing soil nutrients more quickly.d.All of the above

Energy must be transformed in ecosystems because _______.a.energy cannot be created or destroyedb.an organism’s energy must go somewherec.an organism’s energy must come from somewhered.all of the above

Which pair of molecules both contain carbon atoms?

Wildfires open a new seedbed that can be used for new plant growth.