Question 1

When a rabbit eats the lettuce in your garden, the rabbit uses all of the energy in the lettuce. True or False?

Accepted Answer

A) True 
 B)False

Question 2

Why is it so hard to make definite predictions about the amount and timing of global warming as a result of greenhouse gases?

Accepted Answer

The answer of Why is it so hard to make...

Question 3

Which nutrient cycle lacks an atmospheric reservoir?

Accepted Answer

A) nitrogen 
B) oxygen 
C) water 
D) carbon 
E) phosphorus

Question 4

As part of a research project, a graduate student creates an artificial environment in a sealed container. She sterilizes the soil and adds plants, snails, shrews, and a snake. After adding a small artificial pond, she seals the container. During the first several weeks, the plants are thriving and the animals are doing well. However, piles of dropping are beginning to accumulate, and the entire floor of the container becomes covered with a layer of plant debris several inches thick. One probable cause for the problems is that the graduate student didn't:

Accepted Answer

A) add any decomposers. 
B) put in enough plants. 
C) include any herbivores. 
D) include any carnivores. 
E) include any autotrophs.

Question 5

How much of the energy that reaches Earth's outer atmosphere from the sun is available for photosynthesis in plants at Earth's surface?

Accepted Answer

A) 25% 
B) 21% 
C) 14% 
D) 5% 
E) 1%

Question 6

Acid precipitation is the result of interference with the ________ cycles.

Accepted Answer

A) sulfur and nitrogen 
B) sulfur and hydrologic 
C) hydrologic and nitrogen 
D) hydrologic and phosphorus 
E) sulfur and phosphorus

Question 7

Phosphate fertilizers have increased the amount of phosphate in lakes and other bodies of water. What effect does this increase have on the producers in the water?

Accepted Answer

A) It kills them. 
B) It stimulates their growth. 
C) It increases their likelihood of being eaten. 
D) It causes them to form toxic compounds. 
E) It reduces their photosynthetic capacity.

Question 8

A rancher begins raising sheep on the land next to the habitat shown. After losing several lambs, he removes all the wolves. By the next year, he can expect to find:

Accepted Answer

A) an increased hare population. 
B) a decreased owl population. 
C) a decreased antelope population. 
D) a decreased pheasant population.

Question 9

Micronutrients:

Accepted Answer

A) are needed in smaller quantities than macronutrients but are just as essential. 
B) are smaller molecules than macronutrients. 
C) benefit organisms if they are present but are not essential. 
D) include water, carbon, nitrogen, and phosphorus. 
E) are rarely found in the environment.

Question 10

A carnivore is usually a(n):

Accepted Answer

A) primary producer. 
B) secondary producer. 
C) primary consumer. 
D) secondary consumer. 
E) autotroph.

Question 11

The amount of energy captured by plants and made available to consumers in an ecosystem is called:

Accepted Answer

A) net primary productivity. 
B) energy pyramid. 
C) biological magnification. 
D) nutrient cycling. 
E) secondary trophic level.

Question 12

Nitrogen fixation:

Accepted Answer

A) is due to a lack of decomposers and causes nitrogen to accumulate in dead organic matter. 
B) is the conversion of ammonia to nitrate. 
C) is the conversion of nitrate to ammonia. 
D) is undertaken by denitrifying bacteria. 
E) is the synthesis of ammonia from nitrogen gas by certain bacteria.

Question 13

Based on the illustration, the most productive biome is the:

Accepted Answer

A) estuary. 
B) continental shelf. 
C) coniferous forest. 
D) tropical rain forest. 
E) grassland.

Question 14

Autotrophs gain energy from:

Accepted Answer

A) primary producers. 
B) secondary consumers. 
C) secondary producers. 
D) omnivores. 
E) the sun and inorganic nutrients.

Question 15

Bacteria and fungi that secrete enzymes into the surrounding environment to break down wastes and dead organic matter are ________.

Accepted Answer

The answer of Bacteria and fungi that secrete enzymes into...

Question 16

Plants produce biomass by taking in energy, CO2, and nutrients from the environment; consumers eat much of this biomass, but not all. However, ecosystems do not indefinitely accumulate large quantities of organic matter over time. Why not?

Accepted Answer

The answer of Plants produce biomass by taking in energy,...

Question 17

Burning coal and oil to release energy also releases ________, which are overloading Earth's nutrient cycles.

Accepted Answer

A) sulfur, carbon, and nitrogen 
B) sulfur, oxygen, and acid 
C) phosphorus, carbon, and nitrogen 
D) oxygen, methane, and sulfur 
E) nitrogen, phosphorus, and potassium

Question 18

Why might eating high on the food chain subject humans to higher concentrations of certain toxic substances than eating low on the food chain?

Accepted Answer

The answer of Why might eating high on the food...

Question 19

Oceans, the atmosphere, and fossil fuels are large reservoirs of:

Accepted Answer

A) nitrogen. 
B) oxygen. 
C) water. 
D) carbon. 
E) phosphorus.

Question 20

Why is the concentration of carbon dioxide rapidly increasing in Earth's atmosphere?

Accepted Answer

A) Earth is warming. 
B) More photosynthesis is occurring. 
C) The ozone layer has become much thinner. 
D) Many human activities release carbon dioxide. 
E) The oceans are cooling.

Exam 28: How Do Ecosystems Work