Because the products of photosynthesis are used as the reactants of respiration, photosynthesis and respiration are considered:
complementary
Photosynthesis and respiration affect atmospheric CO2 levels on a _____ timescale, whereas volcanic eruptions affect atmospheric CO2 levels on a _____ timescale.
yearly; century
Decomposers are vital components of a food web because they:
return carbon (as CO2) to the atmosphere.
In marine ecosystems, phosphorus is added to the ecosystem primarily from:
erosion of rocks on land.
A botanist is comparing the metabolic pathways for photosynthesis in cyanobacteria and redwood trees. What do you expect that she will find?
These two pathways will actually be quite similar, though subtle differences may exist.
Which of the answer choices is not considered a photosynthetic organism and, therefore, does not remove atmospheric CO2?
human
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 c
TRUE
If all of the tertiary consumers were removed from an environment, the associated food web, and thus the carbon cycle, would collapse.
FALSE
Which of the answer choices is a form of nitrogen that can be utilized by plants?
NO3-
Which of the statements explains how an oxygen-rich atmosphere became possible on Earth?
Rates of oxygen consumption are lower than rates of photosynthesis.
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 he most likely differentiate between these forms of carbon?
by the number of neutrons in 12C, 13C, and 14C
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
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
Phosphorus released from sedimentary rocks through chemical weathering can be immediately assimilated by primary producers and contributes to the biomass of primary producers in an ecosystem.
TRUE
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).
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 equation CaSiO3 + CO2 ? CaCO3 + SiO2 takes into account which of these processes associated with the long-term carbon cycle?
chemical weathering
In terrestrial ecosystems, nitrogen is returned to the atmosphere by:
denitrifying bacteria
Imagine that scientists have discovered a new planet that is apparently devoid of life but has ice caps located at the poles. These ice caps reveal that the planet's atmospheric O2 levels sharply increased about 1,000,000 years ago but then quickly droppe
Photosynthetic organisms evolved on the planet 100,000 years ago but went extinct 50,000 years ago.
Which of these 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 majority of carbon stored in abiotic reservoirs is in the form of:
CaCO3
It is thought that approximately 90% of plant species went extinct during the Carboniferous Period, approximately 320-290 million years ago. Which of the graphs represent the changes that likely occurred in carbon dioxide and oxygen levels? The solid blac
graph H
Recall that sedimentary rocks, living organisms, oceans, and soil are all carbon reservoirs. If the carbon in each of these reservoirs was instantly transformed into atmospheric CO2, which reservoir would contribute the most CO2 to the atmosphere?
sedimentary rocks
Glacial expansion correlates with _____ amounts of CO2 in the atmosphere and temperatures _____ than those measured in 1950.
decreasing; lower
If steelhead were removed from the web, what would you predict would happen to the numbers of tuft-weaving chironomids?
They would decrease.
The first law of thermodynamics states that energy can be transformed from one state to another, but it cannot be created or destroyed. Taking this into consideration, what can be said about the energy transferred between levels in a trophic pyramid?
Some of the energy in a trophic level is converted to heat and is unavailable to the next level of the trophic pyramid.
The carbon and nitrogen cycles are related to one another because:
microorganisms have important roles in the cycling of each.
both are liberated into the environment when organisms decompose.
both are required to make the primary biological molecules (carbohydrates, fats, proteins and sugars).
All of these choices are c