BLY Ch.46

food web

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.

ecosystem.

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

by the number of neutrons in 12C, 13C, and 14C

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

primary producers.

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

return carbon (as CO2) to the atmosphere.

Decomposers are vital components of a food web because they:

energy contained in organic compounds

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

5

If 5000 kilograms (kg) of biomass are available at the primary consumer level, how many kg of biomass would be available to the tertiary consumers?

Atmospheric CO2 levels were higher during the Cambrian Period than today.

Imagine that a research team has discovered a leaf fossil from the Cambrian Period that is 500 million years old. They notice that the leaf had very few stomata compared to present-day leaves. What does this tell the researchers about atmospheric CO2 levels during the Cambrian Period?

Photosynthetic organisms evolved on the planet 100,000 years ago but went extinct 50,000 years ago.

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 dropped 50,000 years ago. What could account for these changes in atmospheric O2 levels?

erosion of rocks on land.

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

highest; lowest

In the Northern Hemisphere and Southern Hemisphere, the rate of photosynthesis is _____ in the summer and _____ in the winter.

food web

Nutrient cycling through ecosystems can be depicted using a(n):

true

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

Primary consumers obtain carbon, nitrogen, and phosphorus through ingestion of primary producers.

Photosynthetic, woody plants first appeared during this period.

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

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

Researchers are measuring Earth's atmospheric CO2 levels, gathering data on CO2 levels in northern and then southern hemispheres. What do you expect that they will find?

long-term carbon; short-term carbon

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.

false

The diverse array of photosynthetic plants and microbes is the result of different sources of CO2 and has little to do with environmental conditions.

true

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.

CaCO3.

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

photosynthesis.

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

photosynthesis.

The movement of Earth's crust, plate tectonics, contributes to the long-term carbon cycle through all of the answer choices except: volcanic activity. photosynthesis. mountain lifting. subduction.

greenhouse

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.

primary comsumers

To which group do herbivores belong in a food web?

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

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?

soil oceans organisms the atmosphere

Which of the answer choices is a reservoir of carbon?

the burning of fossil fuels

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

Rates of oxygen consumption are lower than rates of photosynthesis.

Which of the statements explains how an oxygen-rich atmosphere became possible on Earth?

primary producers

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

a grasshopper

Which of these organisms is considered a primary consumer?

living organisms < the atmosphere < soil < sedimentary rocks

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