Question 1

________ convert nitrogen from nitrates to N₂.
A) Nitrifying bacteria
B) Nitrogen-fixing bacteria living in the soil
C) Denitrifying bacteria
D) Nitrogen-fixing bacteria living in the root nodules of legumes

Accepted Answer

Denitrifying bacteria convert nitrates back into nitrogen gas (N₂), which is released into the atmosphere. This process is important in the nitrogen cycle because it helps to limit the amount of nitrogen in the soil and prevent excessive nitrate runoff into rivers and lakes.

Question 2

Species found in only one place on Earth are called ________ species.
A) hot spot
B) exotic
C) keystone
D) endemic

Accepted Answer

Endemic species are those that are found only in one particular place on Earth. This could be on a small island, in a specific region or habitat, or in a particular country. These species are unique and often face a greater risk of extinction if their habitat is destroyed or altered. Examples of endemic species include the lemurs of Madagascar and the kangaroos of Australia.

Question 3

Sustainable development ________. I)will require making difficult decisions regarding the environment and lifestyle
II)must be achieved if the human species is to survive
III)will require global,multinational cooperation
A) I only
B) II only
C) III only
D) I, II, and III

Accepted Answer

Sustainable development will require making difficult decisions regarding the environment and lifestyle, must be achieved if the human species is to survive, and will require global, multinational cooperation. All three options are necessary components of achieving sustainable development.

Question 4

A regional assemblage of interacting ecosystems is a ________.
A) community
B) landscape
C) movement corridor
D) hot spot

Accepted Answer

A regional assemblage of interacting ecosystems is called a landscape. A community refers to a group of organisms living in the same area and interacting with each other, while a movement corridor is a linear pathway that allows for movement of species between habitats. A hot spot is an area with a high level of biodiversity and endemic species.

Question 5

The major abiotic reservoir for phosphorus is ________.
A) the oceans
B) the atmosphere
C) rock
D) dead organic matter

Accepted Answer

Phosphorus is mainly found in rock, particularly in the form of phosphate minerals. It does not cycle through the atmosphere like some other elements and is not as abundant in the oceans as other nutrients, such as nitrogen. Dead organic matter can temporarily hold phosphorus, but it is ultimately released back into the environment through decomposition.

Question 6

Plants can most readily utilize the ________ form of nitrogen.
A) nitrous oxide
B) N₂
C) amino
D) nitrate

Accepted Answer

Plants can most readily utilize nitrate (NO₃-) form of nitrogen. Nitrate is the most common form of nitrogen in soil and is easily taken up by plant roots. Nitrate is formed from other nitrogen compounds through the process of nitrification.

Question 7

Small areas that have a large number of endangered and threatened species are referred to as ________.
A) biologically magnified
B) endemic environments
C) biodiverse environments
D) biodiversity hot spots

Accepted Answer

Biodiversity hot spots are small areas that have a high concentration of endangered and threatened species. These areas are important to identify and protect in order to conserve biodiversity.

Question 8

The atmosphere is approximately 80% ________ gas.
A) CO₂
B) H₂O
C) CH₄
D) N₂

Accepted Answer

The atmosphere is primarily made up of nitrogen gas, which makes up about 78% of the air we breathe. Carbon dioxide (CO₂) makes up only 0.04% of the atmosphere, while water vapor (H₂O) and methane (CH₄) are present in much smaller quantities.

Question 9

Movement corridors are ________.
A) always created by humans
B) found only along stream sides
C) not harmful, but are beneficial because they allow for dispersal
D) harmful because they allow for the spread of disease and beneficial because they allow for dispersal

Accepted Answer

The answer of Movement corridors are ________.
A) always created by...

Question 10

The rate at which an ecosystem's producers convert solar energy to chemical energy stored in biomass is called ________.
A) energy flow
B) chemical cycle
C) primary productivity
D) trophic structure

Accepted Answer

Primary productivity is a measure of the rate at which energy is captured and stored as organic matter by photosynthetic organisms. It is the foundation of all ecological communities and the basis for nearly all food webs.

Question 11

Landscape ecology ________.
A) is the application of ecological principles to the study of land-use patterns
B) focuses primarily on how to restore human-altered ecological systems
C) deals primarily with ecosystems in urban settings
D) deals with the study of the ranges of different species

Accepted Answer

Landscape ecology is the study of the ecological processes operating in landscapes and how they are affected by land-use patterns. It involves the application of ecological principles to the study of land-use patterns.

Question 12

The primary goal of conservation biology is to ________.
A) catalog species
B) maximize the land set aside for wildlife
C) integrate human culture back into nature
D) counter the loss of biodiversity

Accepted Answer

The primary goal of conservation biology is to counter the loss of biodiversity, which includes the preservation and restoration of habitats and species. The other choices (A, B, and C) are too narrow to encompass the broad focus of conservation biology.

Question 13

With regard to nutrient pollution in aquatic ecosystems,when is the worst time to apply fertilizer to your lawn?
A) when it is raining, or is about to rain
B) when it is cold, or is about to get cold
C) at the same time you apply pesticides
D) at night

Accepted Answer

Applying fertilizer when it is raining, or is about to rain, increases the likelihood of the fertilizer washing away into nearby water bodies, causing nutrient pollution. It is recommended to apply fertilizer when the weather is dry and calm to ensure that the fertilizer stays in place and is absorbed by the soil.

Question 14

Modern conservation science increasingly aims at ________.
A) protecting federally listed endangered species
B) countering pollution
C) sustaining entire ecosystems
D) maintaining genetic diversity within species

Accepted Answer

While protecting endangered species and maintaining genetic diversity are certainly important goals of conservation science, the field is increasingly focused on sustaining entire ecosystems. This approach recognizes that ecosystems are complex webs of interdependent species, and that preserving their functioning is critical to maintaining biodiversity and providing important ecosystem services. Additionally, ecosystem-focused conservation often involves addressing broader human activities that can impact ecosystems, such as land use and resource extraction.

Question 15

On average,what percentage of the energy in one trophic level becomes incorporated into the next higher trophic level?
A) 10%
B) 30%
C) 50%
D) 90%

Accepted Answer

On average, only about 10% of the energy in one trophic level becomes incorporated into the next higher trophic level. This is due to the inefficiency of energy transfer between trophic levels through the process of consumption and digestion. The vast majority of energy is lost as heat or used for metabolic processes within the organism at the lower trophic level.

Question 16

Which type of ecosystem has low primary production but nonetheless contributes a large proportion of Earth's total net primary production?
A) tropical rain forest
B) coral reef
C) open ocean
D) desert

Accepted Answer

Open ocean ecosystems have low primary production, but they cover a large percentage of the Earth's surface, resulting in a significant contribution to the total net primary production. Coral reefs and tropical rainforests have high primary production, and deserts have low primary production and do not contribute as much to the total net primary production compared to the open ocean.

Question 17

Why are most food chains limited to three to five trophic levels?
A) The higher the trophic level, the larger the organism; the larger the organism, the less likely it will be prey.
B) The nutritional quality of existing biomass decreases with increasing trophic level.
C) Most ecosystems have insufficient space to support the increased number of organisms that more trophic levels would require.
D) There is insufficient energy to support more trophic levels.

Accepted Answer

As energy is lost at each trophic level, there is insufficient energy to support more than three to five trophic levels. This is known as the 10% rule, where only 10% of the energy from one trophic level is transferred to the next trophic level. Therefore, additional trophic levels would not have enough energy to sustain organisms.

Question 18

Besides the atmosphere,abiotic reservoirs of carbon dioxide include ________.
A) fossil fuels and dissolved carbon compounds in the oceans
B) rocks and dissolved carbon compounds in the oceans
C) fossil fuels only
D) rocks only

Accepted Answer

The answer of Besides the atmosphere,abiotic reservoirs of carbon dioxide...

Question 19

Which of these organisms convert atmospheric nitrogen gas to a form that can be utilized by plants?
A) bacteria
B) protists
C) animals
D) fungi

Accepted Answer

Only bacteria have the ability to convert atmospheric nitrogen gas into a form that can be utilized by plants, through a process called nitrogen fixation. Protists, animals, and fungi do not have this capability.

Question 20

A movement corridor ________.
A) is a path used by migratory animals when they move to their winter habitats
B) is the path most commonly used by an animal within its home range
C) connects otherwise isolated patches of quality habitat for a species
D) is a natural component of the environment

Accepted Answer

A movement corridor connects otherwise isolated patches of quality habitat for a species. This allows for the movement of individuals and gene flow between populations, which is important for maintaining genetic diversity and population viability. Movement corridors can be natural, such as rivers or mountain ranges, or they can be created through human-made structures like wildlife crossings over highways.

Quiz 20: Communities and Ecosystems

________ convert nitrogen from nitrates to N₂.

Species found in only one place on Earth are called ________ species.

Sustainable development ________. I) will require making difficult decisions regarding the environment and lifestyle II) must be achieved if the human species is to survive III) will require global,multinational cooperation

A regional assemblage of interacting ecosystems is a ________.

The major abiotic reservoir for phosphorus is ________.

Plants can most readily utilize the ________ form of nitrogen.

Small areas that have a large number of endangered and threatened species are referred to as ________.

The atmosphere is approximately 80% ________ gas.

Movement corridors are ________.

The rate at which an ecosystem's producers convert solar energy to chemical energy stored in biomass is called ________.

Landscape ecology ________.

The primary goal of conservation biology is to ________.

With regard to nutrient pollution in aquatic ecosystems,when is the worst time to apply fertilizer to your lawn?

Modern conservation science increasingly aims at ________.

On average,what percentage of the energy in one trophic level becomes incorporated into the next higher trophic level?

Which type of ecosystem has low primary production but nonetheless contributes a large proportion of Earth's total net primary production?

Why are most food chains limited to three to five trophic levels?

Besides the atmosphere,abiotic reservoirs of carbon dioxide include ________.

Which of these organisms convert atmospheric nitrogen gas to a form that can be utilized by plants?

A movement corridor ________.