FBIII Exam III

Dead zones are marine areas with Too low nutrients to support life Too low temperature to support life Too high nutrients which cause bacterial growth and oxygen depletion Too high temperatures which cause bacterial growth and oxygen depletion

Too high nutrients which cause bacterial growth and oxygen depletion

Energy can be formally defined as A) the random motion of molecules. B) the ability to do work or produce heat transfer. C) a force that is exerted over some distance. D) anything that occupies space.

the ability to do work or produce heat transfer

Human beings have dramatically altered the movement of nitrogen from ________. oceans to soils soils to the atmosphere the atmosphere to various pools on the earth's surface proteins to inorganic ions in soils

the atmosphere to various pools on the earth's surface

Biogeochemical cycles: pertain only to the abiotic environment. only pertain to exchanges and interactions that occur within the atmosphere. are used to describe the attempts of humans to recycle various pollutants describe the movement of nutrient elements throughout the abiotic and biotic environment. only include processes conducted by or within living organisms

describe the movement of nutrient elements throughout the abiotic and biotic environment

An energy or biomass pyramid, such as those shown in the powerpoint for class, implies that eating grain-fed beef is an inefficient way to obtain the energy captured by photosynthesis. only half the energy in a trophic level is transferred on to the next-higher level. as energy is transferred from one trophic level to another, about 10% of the energy is lost. most of the energy in a trophic level is incorporated into the next-higher level. the most efficient transfer of energy is from producers to primary consumers.

eating grain-fed beef is an inefficient way to obtain the energy captured by photosynthesis.

In accordance with the 2nd Law of Thermodynamics, in any energy transformation, some of the energy usually ends up as potential energy that flows into the environment. heat energy that flows into the environment. chemical energy that performs useful work. mechanical energy that performs useful work.

heat energy that flows into the environment.

Assimilation =

ingestion - egestion

Immobilization

inorganic N from environment is taken up and incorporated into biomolecules by bacteria

denitrification

inorganic N is used by bacteria (instead of O2) as they break down sugars in anoxic conditions

Studies have demonstrated that for marine ecosystems higher ______ concentrations are generally associated with ______ algal biomass. nitrogen, lower phosphorus, lower nitrogen, higher phosphorus, higher

nitrogen, higher

Carbon is being added to the atmosphere by all of the following EXCEPT cellular respiration by animals. cellular respiration by plants. combustion (burning) of wood. photosynthesis

photosynthesis

Net primary productivity is the primary productivity of an ecosystem, after subtracting energy lost in 1) inedible plant tissues. 2) respiration (maintenance) by primary producers. 3) inefficiencies of photosynthesis. 4) dead plant tissues.

respiration (maintenance) by primary producers.

Carnivores that feed on herbivores (or on detritivores) are referred to as A) keystone species. B) primary producers. C) secondary consumers. D) primary consumers.

secondary consumers

Trophic efficiency is 1) the ratio of net secondary production to assimilation of primary production. 2) the ratio of net production at one trophic level to the net production at the level below, expressed as a percentage. 3) the percentage of production transferred from one trophic level to the next. 4) usually greater than production efficiencies. 5) both B and C

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

Which of the following climate models BEST predicts current climate patterns: those that are based on natural factors only those that are based on human factors only those that incorporate both natural and human factors none of the above does a good job

those that incorporate both natural and human factors

What is the most important role of producers in an ecosystem? A) dissipating heat B) producing organic detritus for decomposers C) using solar energy to convert inorganic compounds into high energy organic compounds D) recycling energy from other trophic levels E) absorbing solar radiation

using solar energy to convert inorganic compounds into high energy organic compounds

A measure of water quality is dissolved oxygen (DO). In an experiment we could determine that decomposition has occurred if the DO level in a water sample was low was high remained unchanged water changed color

was low

A(n) ______________ is all the land drained by a particular river. reservoir water table aquifer watershed

watershed

Which of the following is the chemical equation for photosynthesis? 6 H2O + 6 CO2 + Solar Energy --> C6H12O6 + 6 O2 6 H2O + 6 CO2 --> C6H12O6 + 6 O2 + Solar Energy C6H12O6 + 6 O2 + Solar Energy --> 6 H2O + 6 CO2 C6H12O6 + 6 O2 --> 6 H2O + 6 CO2 + Work and Heat

6 H2O + 6 CO2 + Solar Energy --> C6H12O6 + 6 O2

Nitrogen is an essential component of A) amino acids B) proteins. C) carbohydrates D) A and B E) A, B, and C

A and B

Organisms in which of the following groups can be primary producers? A) cyanobacteria B) zooplankton C) flowering plants and ferns D) A and C only E) A, B, and C

A and C only

Which of the following statements describes a sustainable resource? Any resource that results from the combustion of biomass Any resource that is not a fossil fuel A resource that is consumed slower or equal to the rate at which it is produced A resource that is consumed at a rate faster than the rate at which it is produced

A resource that is consumed slower or equal to the rate at which it is produced

All else being equal, which of the following species would you expect to be most able to evolve and keep pace with climate change? A species that reproduces twice a year, and is part of a large, genetically diverse population A species that reproduces once every two years, and is part of a large, genetically diverse population A species that reproduces twice a year, and is part of a small population with moderate genetic diversity A species that reproduces once every two years, and is part of a small population with moderate genetic diversity

A species that reproduces twice a year, and is part of a large, genetically diverse population

One of your classmates claims that algal growth is the primary driver of oxygen depletion during blooms, because as algae grow they consume oxygen. How would a biologist respond to this claim? Algae do not consume oxygen as they grow. Algae only release oxygen into their environment as they photosynthesize. Algae do consume oxygen as they grow, but the driver of hypoxia during algae blooms is the result of the toxins that some species of algae produce. Yes, algae consume oxygen as they grow and are the primary driver of hypoxia during algae blooms. Algae do consume oxygen as they grow, but they also produce oxygen through photosynthesis. Algae do not drive oxygen depletion.

Algae do consume oxygen as they grow, but they also produce oxygen through photosynthesis. Algae do not drive oxygen depletion

In March of 2012, much of North America experienced unusually warm temperatures. For example, Chicago had 9 days in a row of record high temperatures. High temperatures were more than 8.3°C above the long-term average for 12 straight days. Given these observations, which of the following statements about this heat wave is true? (Source: AccuWeather.com) Because climate change has only caused average global temperatures to rise about 1°C, climate change can't be responsible for the high temperatures. This increase is due solely to the urban heat island effect and thus cannot possibly be associated with climate change. Although this heat wave may be unrelated to climate change, temperature extremes are more likely in a warmer climate. The record high temperatures observed in Chicago during 2012 are clearly a result of climate change.

Although this heat wave may be unrelated to climate change, temperature extremes are more likely in a warmer climate.

Which of the following would you predict to have the greatest production efficiency? An ectothermic herbivore An ectothermic carnivore An endothermic herbivore An endothermic carnivore

An ectothermic carnivore

Which of the following does NOT affect a species' ability to evolve by natural selection to keep pace with climate change? The amount of genetic diversity in the population The species' generation time The ability of individuals to acclimate to a changing environment Whether or not some individuals in the species have traits that lead to improved reproductive success in a warming world

The ability of individuals to acclimate to a changing environment

Humans are impacting the carbon cycle in many ways. One way is by transferring carbon between the slow carbon cycle, which largely encompasses the geologic subsystem, to the fast carbon cycle. Which of the following anthropogenic impacts to the carbon cycle is doing this? Land-use change leading to deforestation Fire suppression practices The burning of fossil fuels Methane release from agriculture

The burning of fossil fuels

In which of the following global nutrient cycles have humans caused a clear, demonstrable increase in the amount of the nutrient stored in the atmospheric subsystem? The phosphorus cycle The nitrogen cycle The carbon cycle A and C

The carbon cycle

Which of the following is NOT an example of the tragedy of the commons? A fishery decline resulting from the collective impact of numerous fishing boats exceeding their allotted take Climate change resulting from numerous individuals and corporations releasing greenhouse gases into the atmosphere Excessive algal blooms that result when phosphorus in household detergents is discharged into lakes The decreases in a ranch's productivity that result when a rancher allows cattle to overgraze his/her land

The decreases in a ranch's productivity that result when a rancher allows cattle to overgraze his/her land

The amount of energy transferred from an organism on one trophic level to the next trophic level is generally abouy 1) 1% 2) 10% 3) 25% 4) 33%

10%

N-Fixation

Bacteria convert atmospheric N to another inorganic form that organisms can use to build biomolecules

Question 211 / 1 point The following figure shows atmospheric CO2 concentrations that were measured in Mauna Loa, Hawaii. Based on these data, which of the following is true? CO2 concentrations are fluctuating randomly over time. CO2 concentrations vary seasonally. Average CO2 concentrations have increased considerably since these measurements began. Both (A) and (B) Both (B) and (C)

Both (B) and (C)

In terrestrial ecosystems, primary production is typically estimated by measuring changes in ____ over time, rather than ____. Most primary production is performed by _________ organisms. CO2, O2, unicellular O2, biomass, multicellular O2, CO2, unicellular CO2, O2, multicellular

CO2, O2, multicellular

Ecological pyramids based on production (i.e., energy) have the same shape for all ecosystems, with wide bars at the base that narrow with successive trophic levels. This indicates a decline in energy at successive trophic levels. What helps to explain this observation? Energy can neither be created nor destroyed, so the sum of the energy in higher trophic levels (i.e., consumers) must be equal to the energy in the lowest level (i.e., primary producers). The number of organisms in a level tends to decline at higher trophic levels. The biomass of organisms tends to decline at higher trophic levels. Energy transfers are inefficient. Every time energy is transferred between trophic levels, some of the energy is assimilated by the consumer but much of it is lost as heat.

Energy transfers are inefficient. Every time energy is transferred between trophic levels, some of the energy is assimilated by the consumer but much of it is lost as heat.

Which of the following statements about the relationship between eutrophication and algal blooms is true? Eutrophication involves algal blooms. Algae receive limiting nutrients, causing rapid population growth. Algal blooms can cause eutrophication. Algal growth causes limiting nutrients to become available in waterways. Eutrophication directly results in hypoxia. The lack of oxygen drives algal growth, resulting in blooms. Hypoxia leads to eutrophication, and the eutrophic conditions drive algal blooms.

Eutrophication involves algal blooms. Algae receive limiting nutrients, causing rapid population growth.

Macronutrients are needed in small amounts, but play a large role in plant metabolism. True False

False

The major pool of nitrogen in the atmosphere is the direct source of nitrogen for most organisms. True False

False

There is always a strong correlation between weather and climate, so we can use current weather to draw conclusions about climate. True False

False

Why is nitrogen fixation such an important process? Nitrogen fixation can only be done by certain prokaryotes. Nitrogen-fixing capacity can be genetically engineered. Fixed nitrogen is most often the limiting factor in plant growth. Nitrogen fixation is very expensive in terms of metabolic energy.

Fixed nitrogen is most often the limiting factor in plant growth

Which of the following statements about changes in greenhouse gases is FALSE? Measurements made on Mauna Loa indicate that CO2 has increased dramatically since the 950s. Measurements made on Mauna Loa indicate that CO2 fluctuates seasonally. Ice core data indicate that over the past 800,000 years CO2 concentration frequently exceeded its recent level. Much of the CO2 released by humans has been absorbed by the oceans.

Ice core data indicate that over the past 800,000 years CO2 concentration frequently exceeded its recent level.

Which of the following best supports the argument that the first law of thermodynamics (conservation of energy and matter) governs the flow of energy through ecosystems? Energy is required to maintain the structure of and fuel the work done by the various organisms inhabiting a given ecosystem. Energy transfers are inefficient. Every time energy is transferred between trophic levels, some of the energy is assimilated by the consumer but much of it is lost as heat. In all ecosystems, the energy absorbed as heat and captured via primary production is equal to the energy lost as heat and respiration plus the chemical energy stored in biomass. In all ecosystems, some of the energy available to power primary production is never assimilated by the primary producers.

In all ecosystems, the energy absorbed as heat and captured via primary production is equal to the energy lost as heat and respiration plus the chemical energy stored in biomass.

When carbon dioxide dissolves in this ocean, carbonic acid is formed. This leads to higher acidity (ocean acidification), mainly near the surface, which has been proven to inhibit shell growth in marine animals and is suspected as a cause of reproductive disorders in some fish. The cause of the increase in carbonic acid is Global warming Climate change Increased CO2 concentrations in the atmosphere. All of the above

Increased CO2 concentrations in the atmosphere.

Which of the following statements about the drivers of modern climate change is FALSE? Anthropogenic greenhouse gas emissions are the principal driver of the recent increase in global mean surface temperature. Increased solar output is a key driver of the recent increase in global mean surface temperature. Multiple independent lines of evidence indicate fossil fuel combustion is causing atmospheric CO2 levels to increase. Volcanic eruptions can produce temporary (i.e., over a few years) decreases in global mean surface temperature.

Increased solar output is a key driver of the recent increase in global mean surface temperature.

What is the primary way in which humans have affected the global phosphorus cycle since the Industrial Revolution? Increasing rates of geologic output through mining phosphate rock Getting more phosphate from manure sources Increasing dust deposition of phosphorus from the atmosphere Increasing phosphorus sedimentation from the deep ocean

Increasing rates of geologic output through mining phosphate rock

Plant Uptake

Inorganic N from the environment is incorporated by plants

Nitrification

Inorganic N is oxygenated and the energy released is used to synthesize sugars

According to the IPCC, one molecule of methane (CH4) is 86 times more potent as a greenhouse gas than a molecule of carbon dioxide (CO2). What does it mean to say that methane is a greenhouse gas? It absorbs short-wave radiation and re-radiates it back towards Earth. It amplifies incoming solar radiation, causing Earth's temperature to increase. It absorbs long-wave radiation and re-radiates some of it back towards Earth. It reflects thermal energy radiated from Earth's surface back towards Earth.

It absorbs long-wave radiation and re-radiates some of it back towards Earth.

If there were no microorganisms, what would happen to litterfall from plants? It would be mineralized, and more nutrients from litterfall would be available to plants because no immobilization would occur. It would accumulate on the ground as part of the soil organic nutrient pool, and would not be transformed. It would accumulate as part of the soil organic nutrient pool but would eventually be taken up by plants. It would cycle normally. Microorganisms are not important in nutrient transformations involving plant litter, they primarily fix nutrients.

It would accumulate on the ground as part of the soil organic nutrient pool, and would not be transformed.

How are matter (e.g., nutrient elements) and energy used in ecosystems? Matter is used in ecosystems; energy is not Matter is recycled through ecosystems; energy is not. Energy is recycled through ecosystems; matter is not. Matter is what brings about change; energy provides the substance of things.

Matter is recycled through ecosystems; energy is not

You want to measure the respiration (Ra) of your favorite houseplant. To do this, you first you place it in a clear chamber, and then do what? Measure the amount of CO2 produced at night, and use this value to calculate Ra. Measure the amount of O2 produced during the day, and use this value to calculate Ra Measure the amount of CO2 produced during a full 24-hour period, and use this value to calculate Ra. Measure the amount of CO2 produced during the day, and use this value to calculate Ra.

Measure the amount of CO2 produced at night, and use this value to calculate Ra.

N-Fixation Equation

N2 to NH4

Which of the following transformations occurs during nitrogen fixation? NO3- to Organic Plant N NO3-to N2 NH4+ to NO3- N2 to NH4+

N2 to NH4+

Nitrification Equation

NH4 to NO3

Plant Uptake Equation

NH4/NO3 to Plant org N

Immobilization equation

NH4/NO3 to Soil Org. N

denitrification equation

NO2 to N2

Which of the following statements about modeled projections of future climate change is FALSE? Future warming of Earth's surface is expected to be more pronounced over land than over sea/oceans. Future warming is expected to be more pronounced in the Arctic than in the tropics (near the Equator). Nearly all the variation in projections of future climate change comes from uncertainty about how to model climate. Even if emissions are dramatically curtailed, some aspects of the climate are expected to continue changing over the next century.

Nearly all the variation in projections of future climate change comes from uncertainty about how to model climate.

Which of the following transformations occurs during denitrification? Ammonium is transformed into nitrate. Soil organic nitrogen is transformed into ammonium. Nitrate is transformed into dinitrogen gas. Nitrate is transformed into organic molecules by soil microbes.

Nitrate is transformed into dinitrogen gas

In aquatic ecosystems, primary production is typically estimated by measuring changes in ____ over time, rather than ____. Most primary production is performed by _________ organisms. CO2, O2, multicellular O2, CO2, unicellular O2, biomass, multicellular CO2, O2, unicellular

O2, CO2, unicellular

Mineralization

Organic matter is broken down during decomposition, releasing inorganic N

Rock weathering provides bioavailable forms of many nutrients. Rock weathering is the primary source of bioavailable forms of which of the following nutrients? Carbon Nitrogen Phosphorus All of the above.

Phosphorus

By mining phosphorus reserves, humans have increased the global supply of phosphorus. Which of the following changes to the global phosphorus cycle has not occurred as a result? Plant uptake in the terrestrial subsystem has increased. Phosphorus storage rates in the terrestrial subsystem have increased. Phosphorus flux from rivers to the sea has increased. Phosphorus flux through the atmosphere has increased.

Phosphorus flux through the atmosphere has increased.

You work as an environmental chemist studying water quality in a small town situated around a lake. One summer, the lake experiences a massive algal bloom. Once the algae subside, you decide to perform a nutrient addition bioassay to explore what caused the bloom. The graph below shows the result from your bioassay experiment. People in the town want to reduce the chance of algal blooms in the future. Given your results, on which nutrient input to the lake would you recommend the town focus their limited resources to mitigate (reduce)? Neither N nor P, because the algal bloom was unrelated to these Phosphorus from pet waste that was washed into the lake Both nutrients (N and P) must be mitigated to clean up the lake Nitrogen fertilizer washed into the lake from residential lawns

Phosphorus from pet waste that was washed into the lake

Which flux in the carbon cycle transforms inorganic carbon to organic carbon? Photosynthesis Litterfall Soil respiration Plant respiration

Photosynthesis

Which of the following nitrogen cycle fluxes is not mediated by microbes? Nitrogen fixation Plant uptake Nitrification Denitrification

Plant Uptake

Litterfall Equation

Plant org N to Soil org N

Which of the following is not a process by which nitrogen is fixed? Plants directly fixing nitrogen when they take up nutrients Lightning strikes Anthropogenic fixation, such as in the Haber-Bosch process Certain bacterial and archaeal organisms fixing nitrogen

Plants directly fixing nitrogen

Many scientists argue that the beginnings and ends of ice ages are triggered by small changes in Earth's orbit known as Milankovitch cycles. These changes affect the amount of energy Earth receives from the Sun. According to this theory, ice ages end because orbital changes cause ocean temperatures to climb, which then causes CO2 to be released into the atmosphere. As atmospheric CO2 increases, Earth warms even more, causing more CO2 to be released into the atmosphere and so on. What is this an example of? Negative feedback Attribution Positive feedback Direct effects of climate change

Positive feedback

How does inefficient transfer of energy among trophic levels influence the typically high risk of extinction shared by most top predators? Predators have the highest total biomass Predators have relatively small population sizes compared to lower trophic levels. Predators are more disease-prone than animals at lower trophic levels. all of the above

Predators have relatively small population sizes compared to lower trophic levels.

Complete the following analogy. GPP : NPP :: Assimilation : ________ Egestion Production Respiration Ingestion

Production

Which of the following statements is supported by the data in this figure? Birds have a higher metabolic rate per unit body mass than mammals or reptiles. Reptiles have a lower metabolic rate per unit body mass than birds or mammals. Body size has no effect on metabolic rate. Smaller animals have higher metabolic rates than larger animals.

Reptiles have a lower metabolic rate per unit body mass than birds or mammals

Mineralization equation

Soil org N to NH4

Which of the following factors has the LEAST impact on differences in mean temperature of planets in our solar system? Solar output Average albedo Greenhouse gas content Distance from the Sun

Solar output

If current predictions of future climate warming are accurate, the areas where temperature and precipitation match species optimal ranges may change. A potential consequence of this is Some species ranges will shift toward the equator and downhill. Species ranges will get smaller overall. Some species ranges will shift poleward and uphill. Species ranges will likely increase in size.

Some species ranges will shift poleward and uphill.

Which of the following is a consequence of biological magnification? The lowest level of the food chain is the most severely affected because those organisms are the most directly exposed to toxic chemicals. Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers. The concentration of toxic chemicals gets less and less as it moves up the food chain. Populations of top-level predators are generally smaller than populations of primary consumers.

Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers.

A rise in sea levels is one consequence of global warming. This rise is due not only to melting ice, but to changes in the temperature of the ocean itself. A) True B) False

True

The carbon stored in fossil fuels ultimately came from carbon dioxide fixed during the process of photosynthesis. True False

True

The process of adding excess nutrients to an ecosystem can be seen as a form of pollution and is called eutrophication A) True B) False

True

Which of the following is NOT a greenhouse gas? nitrous oxide (N2O) ammonia (NH3) water (H2O) carbon dioxide (CO2) methane (CH4)

ammonia (NH3)

"Nitrification" is the conversion of ammonia (NH3) to nitrogen gas (N2). carbon compounds to nitrogen compounds. nitrogen gas (N2) to ammonia (NH3). ammonium (NH4+) to nitrate (NO3-).

ammonium (NH4+) to nitrate (NO3-)

Litterfall

as live plant tissues die and fall to ground they enter the soil organic N pool

Respiration =

assimilation - consumer production

If you wanted to convert excess grain into the greatest amount of animal biomass, to which animal would you feed the grain? (Which has the greatest production efficiency?) 1) cattle 2) pigs 3) chickens

chickens

By measuring the CO2 concentration in ice cores, scientists were able to show that atmospheric CO2 concentrations fluctuated substantially over the last 800,000 years and periods of low atmospheric CO2 concentration correspond with warmer interglacial periods. years of below average precipitation. years of above average precipitation. colder ice age periods.

colder ice age periods

"A farmer planted corn in a field. At harvest time, he stored a great amount of corn in his corn cribs. The corn was needed to feed his livestock during the winter. Several mice entered the corn cribs and ate some of the corn. The farmer's cat caught and ate some of the mice. After the cat died, bacteria broke down the substances in the cat's body. These useful materials were returned to the earth." Which represents the food chain described above? corn > mouse > cat > bacteria bacteria > cat > mouse > corn cat > mouse > corn > bacteria corn > cat > mouse > bacteria

corn > mouse > cat > bacteria