BIO 122 CH 46 Launchpad

Because energy transfer is not 100% efficient across trophic levels, an average of about _____ of energy and biomass available at one trophic level is available at the next.

10%

A scientist studying a material has determined that 12C, 13C, and 14C occur in the material in a ratio of 1000:10:1. How did the most likely differentiate between these forms of carbon?

By the number of neutrons 12C, 13C, and 14C

Which of the equations is the chemical reaction for cellular respiration?

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

The majority of carbon stored in abiotic reservoirs is in the form of:

CaCO3

The equation CaSiO3 + CO2 + CaCO3 + SiO2 takes into account which of these processes associated with the long term carbon cycle?

Chemical Weathering

An increased rate of photosynthesis is the most likely explanation as to why atmospheric CO2 levels appear lowest during glacial periods of Earth's history.

False

If all of the tertiary consumers were removed from an environment, the associated food web, and thus the carbon cycle, would collapse.

False

A _____ takes into account the diverse interactions between primary producers, consumers and decomposers. It depicts the flow of carbon through an environment as interdependent of primary producers, consumers, and decomposers.

Food web

A _____ depicts the flow of carbon through an ecosystem, whereas a ____ depicts the transfer of energy.

Food web; Trophic pyramid

Which of these organisms is considered a primary consumer?

Grasshopper

To some extent, Earth's surface reflects solar radiation (in the form of heat), which is subsequently absorbed by certain _____ gases in the atmosphere, such as methane and CO2.

Greenhouse

Which of the following is not considered a photosynthetic organism, and so would not remove atmospheric CO2?

Humans

What can Antarctic ice core samples tell us about atmospheric CO2 levels? Select all that apply.

Ice cores can help scientists estimate atmospheric CO2 levels from hundreds of thousands of years ago. CO2 ice core data confirm CO2 measurements taken directly from the atmosphere.

Which of the statements is true regarding the carbon cycle?

It cycles both carbon and H2O. It evolved before plants appeared on Earth. It involves both long- and short- term processes. It was based on microbes during the early stages of Earth's history.

Which of the answer choices is a form of nitrogen that can be utilized by plants?

NO3

Recall that in the northern hemisphere, atmospheric CO2 levels are highest in early spring and lowest in early fall. What accounts for this seasonal fluctuation in atmospheric CO2 levels?

Photosynthesis

The movement of Earth's crust, plate tectonics, contributes to the long term carbon cycle through all of the answer choices except:

Photosynthesis

Recall that during the Paleozoic Era, atmospheric CO2 levels decreased. Why?

Photosynthetic, woody plants first appeared during this period.

Cyanobacteria, milkweed plants, and oak trees are all considered:

Primary Producers

Which of these organisms can incorporate atmospheric carbon directly into C6H12O6, thereby playing a major role in a food web?

Primary Producers

Decomposers are vital components of a food web because they:

Return carbon (as CO2) to the atmosphere.

Photosynthesis and respiration both play a major role in the _____ carbon cycle and can affect atmospheric CO2 levels on a seasonal or annual basis.

Short term

Which of the answer choices are reservoirs of carbon?

Soil The atmosphere Oceans Organisms

How can scientists distinguish among different sources of CO2 in the atmosphere?

The amount of different carbon isotopes in the CO2 differs based on the source.

Which of the processes is responsible for the change scientists observed in atmospheric concentrations of 12C,13C, and 14C over the last 200 years?

The burning of fossil fuels

Which of the statements is true regarding subduction?

The carbon it removes is eventually returned to the atmosphere by volcanism.

Over the last several decades, what have researchers discovered about atmospheric CO2 levels?

They have increased

Trout and amoebas are both heterotrophs and can inhabit similar environments, such as a freshwater pond. However, these organisms are very different when it comes to their shape and size. Why?

Trout and amoebas evolved to utilize different sources of C6H12O6 (or other organic compounds).

The long term and short term carbon cycles are connected by the fact that some of the carbon contained in C6H12O6 (or other organic molecules) in plants is incorporated into sedimentary rocks or oil: carbon in sedimentary rock and oil is not immediately cycled back to the Atmosphere:

True

Photosynthesis and respiration affect atmospheric CO2 levels on a _______ timescale, whereas volcanic eruptions affect atmospheric CO2 levels on a ______ timescale.

Yearly;Century

A researcher is measuring Earth's atmospheric CO2 levels, gathering data on CO2 levels in northern and then southern hemispheres. What do you expect that she will find?

Because atmospheric CO2 measurements represent global amounts, measurements in the Northern Hemisphere and Southern Hemisphere will be approximately the same.

The carbon and nitrogen cycles are related to one another because:

Both are required to make the primary biological molecules (Carbohydrates, fats, protein, and sugars). Both are liberated into the environment when organisms decompose. Microorganisms have important roles in the cycling of each.

Which of the statements is an accurate reflection of photosynthesis and chemical weathering?

Both processes use CO2 as a reactant; That is, they decrease atmospheric CO2 levels.

A community of organisms and the physical environment it occupies are known together as a(n):

Ecosystem

Examining the relationship between primary producers, primary consumers, and secondary consumers is one way to track the flow of _____ through a system.

Energy contained in organic compounds

In marine ecosystems, phosphorus is added to the ecosystem primarily from:

Erosion of rocks on land

Which of the following relationships best depicts the amount of carbon stored in the atmosphere, sedimentary rocks, living organisms, and soil?

Living organisms < The atmosphere < Soil < Sedimentary Rocks

The ____ cycle deals with geological processes and carbon reservoirs, some of which have been built up or take place over a period of millennia. In contrast, the _____ cycle involves biological processes that are carried out on a daily and/or seasonal basis.

Long-term carbon; Short-term carbon