Chapter 42- AP biology

Consider the food chain grass → grasshopper → mouse → snake → hawk. How much of the chemical energy fixed by photosynthesis of the grass (100%) is available to the hawk?

0.01%

What percentage of solar radiation striking a plant is converted into chemical energy?

1%

10,000 kcal of producer could support approximately _____ kcal of tertiary consumer.

10

Approximately how many kg of carnivore biomass can be supported by a field plot containing 1,000 kg of plant material?

10

Owls eat rats, mice, shrews, and small birds. Assume that, over a period of time, an owl consumes 5,000 J of animal material. The owl loses 2,300 J in feces and owl pellets and uses 2,600 J for cellular respiration. What is the production efficiency of this owl?

4%

Approximately _____% of the energy at one trophic level is passed on to the next highest trophic level.

5-10

Your textbook states, "Like organisms, ecosystems are open systems." Which of the following provide a legitimate example to illustrate this statement? Select all that apply. A population of reef fishes with a high reproductive rate in a mangrove ecosystem may be a source of recruits for a population in an adjacent coral reef ecosystem with a lower reproductive rate. Detritivores in soil consume nonliving organic matter and make the nutrients available to plants. Earth's atmosphere is bombarded by about 1022 joules of solar radiation each day.

A population of reef fishes with a high reproductive rate in a mangrove ecosystem may be a source of recruits for a population in an adjacent coral reef ecosystem with a lower reproductive rate. Earth's atmosphere is bombarded by about 1022 joules of solar radiation each day.

Select the correct statement(s) about a terrestrial food chain. Select all that apply. The total biomass of the top trophic level is greatest because the top consumers are large. About 1% of net primary production is available to secondary consumers. Energy is transferred from decomposers to plants to herbivores to carnivores.

About 1% of net primary production is available to secondary consumers.

Why is it that nitrogen is often a limiting plant nutrient, despite the fact that the atmosphere is 80% nitrogen gas (N2)?

Because plants cannot fix N2

Why does a vegetarian leave a smaller ecological footprint than an omnivore?

Eating meat is an inefficient way of acquiring photosynthetic productivity.

The law of conservation of matter states that matter cannot be created, yet matter is sometimes gained or lost to an ecosystem. What is the reason for this seeming contradiction?

Ecosystems are open systems; therefore, matter can be moved in/out of an ecosystem from/to another ecosystem.

Which statement most accurately describes how matter and energy are used in ecosystems? Matter is used in ecosystems; energy is not. Energy can be converted into matter; matter cannot be converted into energy. Matter flows through ecosystems; energy cycles within ecosystems. Energy flows through ecosystems; matter cycles within and through ecosystems. Matter can be converted into energy; energy cannot be converted into matter.

Energy flows through ecosystems; matter cycles within and through ecosystems.

Which of the following is primarily responsible for limiting the number of trophic levels in most ecosystems? Nutrient cycles involve both abiotic and biotic components of ecosystems. Many primary and higher-order consumers are opportunistic feeders. Decomposers compete with higher-order consumers for nutrients and energy. Energy transfer between trophic levels is almost always less than 20% efficient. Nutrient cycling rates tend to be limited by decomposition.

Energy transfer between trophic levels is almost always less than 20% efficient.

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? It is undigested and winds up in the feces and is not passed on to higher trophic levels. Heat produced by cellular respiration is used by heterotrophs to thermoregulate. It is recycled by decomposers to a form that is once again usable by primary producers. It is used by organisms to maintain their life processes through the reactions of cellular respiration. It is eliminated as feces or is dissipated into space as heat in accordance with the second law of thermodynamics.

It is eliminated as feces or is dissipated into space as heat in accordance with the second law of thermodynamics.

Why is net primary production (NPP) a more useful measurement to an ecosystem ecologist than gross primary production (GPP)?

NPP represents the stored chemical energy that will be available to consumers in the ecosystem.

In ecosystems, why is the term cycling used to describe material transfer, whereas the term flow is used for energy exchange?

Materials are repeatedly used, but energy flows through and out of ecosystems.

Why is a diagram of energy flow from trophic level to trophic level shaped like a pyramid?

Most energy at each level is lost, leaving little for the next.

Why do logged tropical rain forest soils typically have nutrient-poor soils?

Most of the nutrients in the ecosystem are removed in the harvested timber.

Which of the following equations is correct? NPP = GPP − R R = NPP + GPP GPP = NPP − R NPP = GPP + R NPP = GPP/R

NPP = GPP − R

How is it that the open ocean produces the highest net primary productivity of Earth's ecosystems, yet net primary productivity per square meter is relatively low?

Oceans have the largest area of all the ecosystems on Earth.

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? The fish can potentially provide more food for humans than the seal meat can. The total biomass of the fish is lower than that of the seals. Seal populations are larger than fish populations. Polar bears can provide more food for humans than seals can. Seal meat probably contains the highest concentrations of fat-soluble toxins.

The fish can potentially provide more food for humans than the seal meat can.

Which of the following is true of detritivores? They convert organic materials from all trophic levels to inorganic compounds usable by primary producers. They recycle chemical elements directly back to primary consumers. They secrete enzymes that convert the organic molecules of detritus into CO2 and H2O. They synthesize organic molecules that are used by primary producers. Some species are autotrophic, whereas others are heterotrophic.

They convert organic materials from all trophic levels to inorganic compounds usable by primary producers.

How does inefficient transfer of energy among trophic levels result in the typically high endangerment status of many top-level predators?

Top-level predators are destined to have small populations that are sparsely distributed.

What is secondary production?

food that is converted to new biomass by consumers

Which of the following locations is the reservoir for carbon in the carbon cycle? fossilized plant and animal remains (coal, oil, and natural gas) sediments and sedimentary rocks plant and animal biomass atmosphere all of the above

all of the above

For most terrestrial ecosystems, pyramids composed of species abundances, biomass, and energy are similar in that they have a broad base and a narrow top. The primary reason for this pattern is that

at each step, energy is lost from the system because of the second law of thermodynamics.

Which of the following locations is the main reservoir for nitrogen in Earth's nitrogen cycle? sedimentary bedrock fossilized plant and animal remains (coal, oil, and natural gas) soil atmosphere plant and animal biomass

atmosphere

Corn production in many states of the Midwest is limited by nitrogen levels in the soil. Some farmers reduce the need to apply expensive anhydrous ammonia to their fields by rotating corn crops with nitrogen-fixing soybean crops. Using soybeans to add nitrogen to soils is an example of

biological augmentation.

To selectively remove soil toxins from regions affected by Hurricane Katrina, some residents have raised sunflowers and other plants in their yards. Then, the mature plants are pulled up and safely stored with other contaminated wastes. This is an example of

bioremediation.

An ecosystem is unlikely to be limited by the supply of _____ because it is obtained from the air.

carbon

What element is found in all organic compounds?

carbon

Plants obtain carbon from _____.

carbon dioxide

Where do plants get the carbon they use to make organic molecules?

carbon dioxide

_____ are secondary consumers.

carnivores

Which of these provides your body with energy? minerals fats oxygen vitamins light

fats

On a global scale, energy _____ ecosystems whereas chemical elements _____ ecosystems.

flows through ... are recycled in

In a typical grassland community, which of the following is the primary consumer? snake grass hawk grasshopper shrew

grasshopper

Which of the following terms encompasses all of the others? primary consumers carnivores heterotrophs herbivores secondary consumers

heterotrophs

Plants use _____ as a source of energy.

light

Where do plants get the energy to make organic molecules?

light

Aquatic primary productivity is most limited by which of the following? increased pressure with depth temperature pollution predation by primary consumers light and nutrient availability

light and nutrient availability

Which of these is NOT an organic molecule? carbohydrates minerals proteins glucose lipids

minerals

Nitrogen is available to plants mostly in the form of

nitrate and ammonium ions in the soil.

Aquatic ecosystems are most likely to be limited by which of the following nutrients? nitrogen zinc carbon iron potassium

nitrogen

A 3-hectare lake in the American Midwest suddenly has succumbed to an algal bloom. What is the likely cause of eutrophication in freshwater ecosystems, such as this one?

nutrient-rich runoff

Biogeochemical cycles are crucial to ecosystem function because _____.

nutrients and other life-sustaining molecules are in limited supply and must be continually recycled

Which of these ecosystems accounts for the largest amount of Earth's net primary productivity? tundra tropical rain forest open ocean salt marsh savanna

open ocean

A cow's herbivorous diet indicates that it is a(n)

primary consumer.

The relationship between biomass and primary productivity is that _____.

primary productivity is the rate at which biomass is produced

To recycle nutrients, an ecosystem must have, at a minimum,

producers and decomposers.

How does phosphorus normally enter ecosystems?

rock weathering

Consider this segment of a food web: Snails and grasshoppers eat pepper plants; spiders eat grasshoppers; shrews eat snails and spiders; owls eat shrews. The shrew occupies the trophic level(s) of _____.

secondary and tertiary consumers

The amount of chemical energy in a consumer's food that is converted to its own new biomass during a given time period is known as which of the following?

secondary production

The total biomass of photosynthetic autotrophs present in an ecosystem is known as

standing crop.

Which trophic level is most vulnerable to extinction?

tertiary consumer level

Subtraction of which of the following will convert gross primary productivity into net primary productivity? the energy fixed by photosynthesis the energy contained in the standing crop the energy used by autotrophs in respiration all solar energy the energy used by heterotrophs in respiration

the energy used by autotrophs in respiration

Trophic efficiency is

the percentage of production transferred from one trophic level to the next.

The energy for nearly every organism in nearly every ecosystem ultimately comes from _____.

the sun

What is the goal of restoration ecology?

to speed up the restoration of a degraded ecosystem

Which of these ecosystems has the highest net primary productivity per square meter annually? open ocean savanna temperate forest tropical rain forest boreal forest

tropical rain forest

Photosynthetic organisms are unique to most ecosystems because they

use light energy to synthesize organic compounds from inorganic compounds.