Question 1

You own 300 acres of patchy temperate forest. Which one of the following actions would increase the net primary productivity of the area the most?

Accepted Answer

Planting 500 new trees would increase the net primary productivity the most because trees are the primary producers in temperate forests and they play a crucial role in ecosystem functioning by capturing sunlight, producing oxygen, and creating habitats for a variety of organisms. Adding fertilizer could also increase productivity, but it can also have negative impacts on the soil and water quality. Relocating all the deer could reduce browsing pressure on vegetation, but it may not necessarily lead to a significant increase in net primary productivity. Introducing 100 rabbits could even have a negative impact on plant growth as rabbits are known to overgraze on vegetation.

Question 2

Which of the following consume other living organisms?

Accepted Answer

Herbivores consume primary producers (plants), while carnivores consume other animals. Therefore, both B and C consume other living organisms. Primary producers (A) produce their own food through photosynthesis, decomposers (D) break down dead organic matter, but neither consume living organisms.

Question 3

Why are changes in the global carbon cycle important?
I. Burning reduces available carbon for primary producers and, therefore, primary consumers.
II. Deforestation and suburbanization reduce an area's net primary productivity.
III. Increasing atmospheric concentrations of carbon dioxide could alter Earth's climate.
IV. By using fossil fuels, we are destroying a nonrenewable resource.

Accepted Answer

All the given options are reasons why changes in the global carbon cycle are important. Burning reduces available carbon for primary producers and, therefore, primary consumers (I). Deforestation and suburbanization reduce an area's net primary productivity (II). Increasing atmospheric concentrations of carbon dioxide could alter Earth's climate (III). By using fossil fuels, we are destroying a nonrenewable resource (IV). Therefore, option C, which includes all four options, is the correct answer.

Question 4

Why is energy lost when herbivores eat primary producers?

Accepted Answer

Primary producers, such as plants, have energy stored in substances like cellulose, which is indigestible to many herbivores. As a result, a significant amount of energy is lost during digestion and is not available for use by the herbivore.

Question 5

What is the leading hypothesis as to why terrestrial productivity is higher in equatorial climates?

Accepted Answer

The leading hypothesis is that productivity in equatorial climates is higher due to a combination of factors, including greater water availability, available sunlight, and higher temperatures. These factors work together to create an ideal environment for plant growth and photosynthesis.

Question 6

When primary producers expend energy to build new tissue, this is

Accepted Answer

When primary producers, such as plants, expend energy to build new tissue, this energy contributes to net primary productivity, which is the amount of biomass available for consumption by herbivores and other consumers. Thus, it encompasses both the energy invested in new growth (net primary productivity) and the energy available to consumers. Maintenance costs refer to the energy used for processes such as respiration, not directly for building new tissue.

Question 7

If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps involving humans, starting from phytoplankton to zooplankton to fish to seals to polar bears, then which of the following could be true?

Accepted Answer

Since the flow of energy starts from phytoplankton to zooplankton to fish, it is likely that the fish populations are higher than seal populations. This means that fish can potentially provide more food for humans than seal meat. Seals and polar bears may contain higher concentrations of fat-soluble toxins due to bioaccumulation. However, the given food chain does not provide enough information to determine the total biomass of fish and seals.

Question 8

Detritus can be consumed by which of the following primary decomposers?

Accepted Answer

Detritus can be consumed by all of these primary decomposers, including bacteria, fungi, and earthworms. Archaea may also play a role in decomposition, but are not mentioned as commonly associated with it as the other options. Therefore, the best choice is E, all of the above.

Question 9

Figure 53.5
-After looking at the figure above, what can be said about productivity in this ecosystem?

Accepted Answer

The figure shows a pyramid of biomass, with the highest biomass at the base (primary producers) and the lowest biomass at the top (top predators). This indicates that there is a loss of energy and biomass as it moves up the trophic levels. Typically, only 10% of the energy is transferred from one trophic level to the next, while 90% is lost as heat or through other metabolic processes. Therefore, between 80 and 90% of the energy is lost at the next highest trophic level.

Question 10

Figure 53.3
-Which category in the figure above makes available the highest productivity per square meter?

Accepted Answer

Algal beds and reefs have the highest productivity per square meter because they have high primary productivity and support a diverse range of species.

Question 11

Which statement best describes what ultimately happens to the chemical energy that is NOT converted to new biomass in the process of energy transfer between trophic levels in an ecosystem?

Accepted Answer

The second law of thermodynamics states that energy is lost as heat when it is transferred or transformed. Therefore, the energy that is not used to build new biomass would eventually dissipate into space as heat or be eliminated as feces, consistent with the second law of thermodynamics.

Question 12

Which of the following is a consequence of biomagnification?

Accepted Answer

Biomagnification is the increasing concentration of toxic chemicals in higher trophic levels of food chains. As the toxins accumulate in the bodies of organisms at each level, top-level predators are at greater risk because they consume more prey and thus ingest more toxins.

Question 13

At the Hubbard Brook Experimental Forest in New Hampshire, how did large amounts of energy leave the decomposer food web?

Accepted Answer

Large amounts of energy left the decomposer food web at the Hubbard Brook Experimental Forest in New Hampshire due to detritus being washed away into streams during heavy rain. This disrupted the decomposition process and reduced the amount of energy available for consumption in the food web.

Question 14

What is the main reason for using food webs instead of food chains in analyzing ecosystems?

Accepted Answer

Food webs are more accurate than food chains because most organisms eat more than one type of food and feed at several trophic levels. Additionally, the decomposition cycle must be shown in order to fully understand the flow of energy in an ecosystem. Therefore, answers A and B both apply.

Question 15

Figure 53.3
-Which terrestrial category in the figure above has the highest economic impact on Earth's ecosystem?

Accepted Answer

Tropical wet forests have the highest economic impact on Earth's ecosystem as they are home to a significant diversity of plant and animal species that are important to industries such as agriculture, pharmaceuticals, and tourism. Deforestation of these forests also has a significant impact on global carbon emissions and climate change.

Question 16

Figure 53.4
-After looking at the experiment in the figure above, what can be said about productivity in marine ecosystems?

Accepted Answer

The experiment shows that productivity significantly increased when iron was added to the marine environment, indicating that iron can be a limiting nutrient in productivity in marine ecosystems. Option A is incorrect because marine organisms do not break down iron for energy; they use it to create chlorophyll for photosynthesis, which provides them with energy. Option B is incorrect because the data in the figure provide meaningful information about productivity in marine ecosystems. Option C is partially correct, but it is not the most accurate answer because productivity did not increase simply because chlorophyll was added, but because chlorophyll synthesis was facilitated by the added iron.

Question 17

Figure 53.3
-Which habitat type in the figure above covers the largest area on Earth?

Accepted Answer

The open ocean covers about 71% of the Earth's surface, making it the largest habitat type in the figure.

Question 18

How are the components in the figure above linked by the flow of energy?

Accepted Answer

The answer of How are the components in the figure...

Question 19

Figure 53.3
-In the figure above, how is net primary productivity represented?

Accepted Answer

Net primary productivity is organized by biome, as indicated by the different colors in the figure representing different biomes (e.g., green for forests, brown for deserts).

Question 20

Figure 53.3
-Which habitat type in the figure above makes available the most new tissue to consumers?

Accepted Answer

The answer of  Figure 53.3
-Which habitat type in the...

Quiz 53: Ecosystems and Global Ecology

You own 300 acres of patchy temperate forest. Which one of the following actions would increase the net primary productivity of the area the most?

Which of the following consume other living organisms?

Why is energy lost when herbivores eat primary producers?

What is the leading hypothesis as to why terrestrial productivity is higher in equatorial climates?

When primary producers expend energy to build new tissue, this is

If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps involving humans, starting from phytoplankton to zooplankton to fish to seals to polar bears, then which of the following could be true?

Detritus can be consumed by which of the following primary decomposers?

Figure 53.5 -After looking at the figure above, what can be said about productivity in this ecosystem?

Figure 53.3 -Which category in the figure above makes available the highest productivity per square meter?

Which statement best describes what ultimately happens to the chemical energy that is NOT converted to new biomass in the process of energy transfer between trophic levels in an ecosystem?

Which of the following is a consequence of biomagnification?

At the Hubbard Brook Experimental Forest in New Hampshire, how did large amounts of energy leave the decomposer food web?

What is the main reason for using food webs instead of food chains in analyzing ecosystems?

Figure 53.3 -Which terrestrial category in the figure above has the highest economic impact on Earth's ecosystem?

Figure 53.4 -After looking at the experiment in the figure above, what can be said about productivity in marine ecosystems?

Figure 53.3 -Which habitat type in the figure above covers the largest area on Earth?

How are the components in the figure above linked by the flow of energy?

Figure 53.3 -In the figure above, how is net primary productivity represented?

Figure 53.3 -Which habitat type in the figure above makes available the most new tissue to consumers?