Chapter 15. 15·6–15·8 Energy and chemicals flow within ecosystems.

Show What You Know - Self Quiz

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You must read each slide, and complete any questions on the slide, in sequence.

Instructions

Check your understanding of concepts from 15·6–15·8 Energy and chemicals flow within ecosystems by answering the following questions.

1.

1. “Top” carnivores:

rely on symbiotic bacteria living in their digestive systems to help digest cellulose.

consume herbivores primarily.

consume carnivores primarily.

rely directly on primary producers for energy.

are more common than secondary consumers.

Correct. (See section 15·6 Energy flows from producers to consumers.)

Incorrect. (See section 15·6 Energy flows from producers to consumers.)

2.

2. “Lake Erie is Turning to Slime” ran a news headline in March, 2014. The story went on to describe how the waters of Lake Erie are being turned bright green and big communities of fish were being killed off. What is likely causing Lake Erie to “turn into slime”?

a decrease in the nitrogen levels in the water

a decrease of nutrients in the water, which leads to starvation of the fish populations

an increase in the level of phosphorus in the water

an increase in dissolved oxygen in the water

a decrease in the number of bacteria present in the water

Correct. (See section 15·8 Essential chemicals cycle through ecosystems.)

Incorrect. (See section 15·8 Essential chemicals cycle through ecosystems.)

3.

3. The nitrogen cycle is important biologically because:

nitrogen forms the framework for organic molecules essential to all organisms.

nitrogen is a component of amino acids, proteins, and nucleic acids.

nitrogen is a major constituent of phospholipids, ATP, and other energy-storing molecules.

photosynthesis by plants and phytoplankton remove substantial amounts of atmospheric nitrogen.

All of the above are correct.

Correct. (See section 15·8 Essential chemicals cycle through ecosystems.)

Incorrect. (See section 15·8 Essential chemicals cycle through ecosystems.)

4.

4. Secondary consumers are:

carnivores that eat other carnivores.

herbivores.

detritivores.

usually photosynthetic.

carnivores that eat herbivores.

Correct. (See section 15·6 Energy flows from producers to consumers.)

Incorrect. (See section 15·6 Energy flows from producers to consumers.)

5.

5. Which of the following is NOT a characteristic of a eutrophic lake?

rich in nutrients

often results from runoff from fertilizers

high in organic matter

high levels of oxygen

All of the above are characteristics of a eutrophic lake.

Correct. (See section 15·8 Essential chemicals cycle through ecosystems.)

Incorrect. (See section 15·8 Essential chemicals cycle through ecosystems.)

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