Question 1

Other than the polar tundra,the LEAST productive terrestrial biomes tend to be

Accepted Answer

Deserts have extremely low rainfall and limited water resources, which makes them the least productive terrestrial biomes. The scarcity of water limits plant growth and reduces the amount of food available for animals, leading to lower levels of productivity.

Question 2

What best explains the following observation: consumers directly use approximately 20 percent of a forest's net primary productivity (NPP),whereas decomposers directly use approximately 80 percent?

Accepted Answer

Consumers typically eat only certain parts of organisms, such as fruits or muscle tissue, whereas decomposers break down the entire body of the food organism, thus directly using more of the NPP.

Question 3

Several research teams have questioned Daniel Boyce's data that indicates a loss of 500 million tons of phytoplankton a year from Earth's oceans.Is it important for researchers to accurately determine trends in net primary productivity (NPP)in the oceans because

Accepted Answer

It is important for researchers to accurately determine trends in net primary productivity (NPP) in the oceans because the loss of 500 million tons of phytoplankton each year could have a negative effect on the ocean's NPP and all of the ocean life that depends upon it. Therefore, it is crucial to accurately determine these trends in order to properly manage and protect the ocean ecosystem. Option A is incorrect because although there are similarities between NPP requirements on land and in the ocean, this is not the main reason why accurate determination of NPP trends is important. Option B and D are incorrect because there is no evidence to suggest that the loss of 500 million tons of phytoplankton would have a positive effect on NPP or ocean life.

Question 4

A variety of species living together and interacting with each other in a defined place form an ________.

Accepted Answer

The answer of A variety of species living together and...

Question 5

Why are deserts and tundra among the least productive terrestrial biomes?

Accepted Answer

Water availability and extreme temperature conditions are important limiting factors in net primary productivity (NPP) in desert and tundra biomes. Both biomes have limited access to water, which makes it difficult for plants to grow and survive. Additionally, desert biomes experience extreme heat, while tundra biomes experience extreme cold, further limiting NPP. These factors contribute to why deserts and tundra are among the least productive terrestrial biomes.

Question 6

Ecologists often define an ecosystem with regard to how BOTH ________ are acquired and distributed by the biotic community.

Accepted Answer

The answer of Ecologists often define an ecosystem with regard...

Question 7

Between late 1997 and mid-2008,satellites observed that warmer-than-average ocean temperatures led to below-average chlorophyll concentrations in the oceans.This finding suggests that continued warming of Earth's oceans could lead to a(n)________ in net primary productivity in the oceans,and the oceans would,therefore,remove ________ carbon dioxide from the atmosphere.

Accepted Answer

Warmer-than-average ocean temperatures can lead to a decrease in chlorophyll concentrations, which is a proxy for a decrease in net primary productivity (NPP). NPP refers to the rate at which plants and algae convert carbon dioxide into organic matter through photosynthesis. Therefore, a decrease in NPP means that less carbon dioxide is being removed from the atmosphere.

Question 8

To best use Earth's net primary productivity to feed the most people,diets should be modified to include only ________,moving ________ the food chain and gathering the maximum amount of energy available from a given biomass of producers.

Accepted Answer

Diets should be modified to include only plant material, which is lower down the food chain, to obtain the maximum amount of energy available from a given biomass of producers. This way, energy is not lost through trophic levels, and more people can be fed with the available net primary productivity.

Question 9

An ecosystem that experiences a small increase in nutrients available to primary producers is likely to show

Accepted Answer

With an increase in nutrients, primary producers are able to carry out photosynthesis more efficiently, leading to increased net primary productivity.

Question 10

Other than tropical forests,the most productive biomes tend to be

Accepted Answer

Estuaries are highly productive biomes due to the mixing of saltwater and freshwater. This creates a highly nutrient-rich environment that supports a diverse array of plant and animal species. Additionally, estuaries provide important feeding, breeding, and nursery habitats for many aquatic organisms. While deep oceans may have high levels of productivity in certain areas, overall they have relatively low productivity due to the limited availability of sunlight and nutrients. Deserts and tundra are generally considered to have low levels of productivity due to their harsh environmental conditions.

Question 11

The figure below shows the net primary productivity (NPP)in marine biomes around the world with the darkest areas being the most productive.The pattern of NPP in marine ecosystems as shown suggests that

Accepted Answer

The answer of The figure below shows the net primary...

Question 12

Ecologists use a(n)________ to represent the amount of energy available to organisms in an ecosystem.

Accepted Answer

The answer of Ecologists use a(n)________ to represent the amount...

Question 13

Each level of an energy pyramid corresponds to a step in a food chain and is called a(n)________ level.

Accepted Answer

The answer of Each level of an energy pyramid corresponds...

Question 14

As shown in the figure below,the net primary productivity (NPP)in terrestrial biomes around the world is greatest in areas near the Equator that also receive high amounts of yearly rainfall.This pattern of NPP in terrestrial ecosystems suggests that

Accepted Answer

The pattern of NPP in terrestrial biomes suggests that productivity is greatest in areas near the Equator with high rainfall. This suggests that NPP in terrestrial ecosystems is highly sensitive to temperature and available sunlight, as these factors are typically greatest in Equatorial regions. This is consistent with the fact that plants require sunlight for photosynthesis and that temperature can play a key role in determining the rates of biochemical reactions that underlie plant growth and development. Choice B is incorrect because the figure only pertains to terrestrial biomes, not marine ecosystems. Choice C is incorrect because there are limits to terrestrial productivity, as evidenced by variations in NPP across different biomes. Choice D is incorrect because marine-derived nutrients are not the primary driver of terrestrial productivity, although they can certainly influence it in certain cases (e.g. in riparian zones where nutrients from upstream can enrich soil fertility).

Question 15

Producers capture energy from the ________ and transform it into fuel energy that passes up the food chain as one organism eats another.

Accepted Answer

The answer of Producers capture energy from the ________ and...

Question 16

Which of the following is NOT an easily testable hypothesis regarding net primary productivity?

Accepted Answer

The tastiness of products of NPP is not a measurable or easily testable factor in determining net primary productivity. The other choices are all easily testable hypotheses related to factors that may influence NPP in different ecosystems.

Question 17

Chemical elements required by living organisms are BOTH ________ within and across ecosystems.

Accepted Answer

The answer of Chemical elements required by living organisms are...

Question 18

In marine ecosystems,net primary productivity tends to be

Accepted Answer

Net primary productivity tends to be greater along shorelines where terrestrial nutrients enter the marine environment, leading to higher levels of primary production. This is due to the process of eutrophication, where the nutrients from runoff and decomposition increase the growth of phytoplankton, which supports the rest of the food chain.

Question 19

At each trophic level,a portion of the energy originally captured by producers is lost as ________,typically released as a by-product of cellular respiration.

Accepted Answer

The answer of At each trophic level,a portion of the...

Question 20

A group of living communities interacting with one another and their shared physical environment is a(n)________.

Accepted Answer

The answer of A group of living communities interacting with...

Quiz 21: Ecosystems