Deck 10: Systems and Cycles: Are We Changing Earths Life Support System

Question 1

A system is defined by components interacting to achieve

A) outcomes equal to the components.
B) outcomes the components could not achieve on their own.
C) outcomes the components could achieve on their own.
D) outcomes that would be possible with only some components.

Answer 1

outcomes the components could not achieve on their own.

Question 2

How could Biosphere 2 have been modified to turn it into an open system?

A) add more oxygen gas
B) remove more microbes from the soil
C) block the sunlight from entering
D) remove the glass enclosing the structure

Answer 2

remove the glass enclosing the structure

Question 3

An ecosystem at a park near you is an example of a(n)

A) open system.
B) closed system.
C) emergent property.
D) model.

Answer 3

open system.

Question 4

An ant colony can contain thousands of ants. Each ant has a limited range of behavior, yet the colony as a whole is capable moving huge amounts of dirt, reacting to food sources, and reacting to enemies. This is an example of

A) feedback.
B) a closed system.
C) emergent properties.
D) a model.

Question 5

A complex system like the climate of Earth can be better understood by

A) creating an open system.
B) creating models.
C) eliminating the emergent properties.
D) None of these are correct.

Question 6

Scientists are modeling the population of common loons (Gavia immer) over time on an isolated lake in Canada. What is the stock in this example?

A) the location of the lake in Canada
B) the amount of water in the lake
C) the amount of food available for the loons
D) the number of loons

Question 7

Scientists are modeling the population of common loons (Gavia immer) over time on an isolated lake in Canada. What would be a flow in this example?

A) the addition of water in the lake
B) the decrease in baitfish populations that are prey for the loon
C) more loons arriving and joining the lake population
D) a new species of bird arriving at the lake

Question 8

The Biosphere 2 project did not go as planned, and oxygen gas had to be supplemented into the system. This was due to

A) a higher than expected outflow of oxygen.
B) reduced sunlight.
C) a higher than expected outflow of carbon dioxide.
D) All of these are correct.

Question 9

You suspect that a newly discovered cell is undergoing photosynthesis. You add water and carbon dioxide to the cell and expose it to sunlight. What should be produced in the cell if photosynthesis is occurring?

A) simple sugars such as glucose
B) mitochondria
C) more carbon dioxide
D) chlorophyll

Question 10

There are several types of feedback described in Chapter 10. All of these have which feature in common?

A) They all will amplify negative consequences.
B) They all will impact the levels of stocks.
C) They all will lead to outflows from the system.
D) They all are based on models.

Question 11

Ice cover in the Arctic reflects sunlight and therefore prevents the warming of ocean water. Each year, as less ice accumulates, more sun reaches the water and heats it up, leading to less ice, warmer water and even less ice, and so on. This is an example of

A) balancing feedback.
B) reinforcing feedback.
C) emergent properties.
D) a model.

Question 12

A thermostat connected to a central air conditioning and heating system in your house serves to provide what change in the temperature?

A) balancing feedback
B) reinforcing feedback
C) inflow
D) outflow

Question 13

Tracing the path of nitrogen as it travels through living things and nonliving things would be considered

A) a feedback loop.
B) balancing feedback.
C) a biogeochemical cycle.
D) reinforcing feedback.

Question 14

Oxygen, nitrogen and phosphorus are macronutrients, which means that they

A) are not needed by organisms.
B) are needed by organisms, but in small amounts.
C) are needed by organisms, but in large amounts.
D) must be produced in plants.

Question 15

Which of the following would be a sink for phosphorus?

A) lithosphere
B) biosphere
C) hydrosphere
D) All of these are correct.

Question 16

What process has led to the increasing oxygen concentration on the planet over the last 2.7 billion years?

A) ocean acidification
B) eutrophication
C) nitrification
D) photosynthesis

Question 17

What is the main way in which excess phosphorus and nitrogen get into bodies of water to result in eutrophication?

A) through decomposition
B) through agricultural runoff
C) through the atmosphere
D) through precipitation

Question 18

Nitrogen and phosphorus are both critical for the production of which molecule in human cells?

A) deoxyribonucleic acid (DNA)
B) cellulose
C) glucose and other simple sugars
D) oxygen

Question 19

Scientists are testing the impact of soil on the growth of a plant. They add the plant to soil that has been sterilized (removed of all microbes), and the plant fails to grow. What might be one cause of this finding?

A) a lack of microbes to produce oxygen
B) a lack of microbes that will fix nitrogen
C) a lack of microbes that will perform photosynthesis
D) a lack of nutrients in the soil

Question 20

Diazotrophs are essential to plants because they

A) supply sugar that the plant needs.
B) allow the plant to take up phosphorus.
C) prevent the growth of harmful bacteria.
D) convert nitrogen to a usable form.

Question 21

Nitrogen is converted from its free form to ammonia by which of the following?

A) decomposers
B) lightning strikes
C) nitrogen-fixing bacteria
D) All of these are correct.

Question 22

As plants die, the nitrogen in their cells is converted to by fungi and bacterial decomposers, in a process known as .

A) nitrogen gas (N₂); ammonification
B) ammonia (NH₃); ammonification
C) nitrogen gas (N₂); nitrification
D) ammonia (NH₃); nitrification

Question 23

Scientists have isolated several bacteria from the soil. When they provide nitrogen compounds to these bacteria, they can detect higher amounts of N₂ gas being produced and released. Therefore, these researchers conclude these bacteria are capable of what process?

A) ammonification
B) eutrophication
C) nitrification
D) denitrification

Question 24

What is the primary source of biologically available nitrogen on Earth?

A) synthetic fertilizer
B) mined deposits
C) fossil fuels
D) None of these are correct.

Question 25

If you removed a pea or bean plant from the soil and cut a small slice from a root nodule, what types of cells, other than plant cells, would you expect to find?

A) fungi cells
B) bacterial cells
C) animal cells
D) None of these are correct.

Question 26

The Haber-Bosch process is used to achieve what goal?

A) remove carbon dioxide from the atmosphere
B) fix nitrogen to a usable form
C) create phosphorus-based fertilizer
D) burn fossil fuels to create electricity

Question 27

An area described as a dead zone in the ocean is an area with

A) large amounts of decomposers present.
B) very few fish.
C) low oxygen concentration.
D) All of these are correct.

Question 28

Methanogens are important for the cycling of which macronutrient?

A) carbon
B) phosphorus
C) nitrogen
D) methane

Question 29

The increase in atmospheric levels of is leading to a in the pH of oceans.

A) carbon dioxide; increase
B) carbon dioxide; decrease
C) nitrogen; increase
D) nitrogen; decrease

Question 30

Fossil fuels are a sink for carbon located in the

A) lithosphere.
B) biosphere.
C) hydrosphere.
D) atmosphere.

Question 31

In the carbon cycle, plants carbon dioxide in the atmosphere, and animals carbon dioxide in the atmosphere.

A) remove; add to
B) outcomes the components could not achieve on their own.
C) remove; remove
D) add to; add

Question 32

Is the human body an open or closed system? Justify your answer with examples.

Question 33

Illustrate an example of a stock and flow system. How can we use stock and flow diagrams to understand a system?

Question 34

In eutrophication, if excess nitrogen or phosphorus in a body of water causes the overgrowth of phytoplankton, how is it that this process will result in a reduction of oxygen in the impacted area?

Question 35

Explain the following statement: diazoytrophs are essential for the production of nitrogen that is consumed by humans.