What is the step in the nitrogen cycle in which gaseous nitrogen is converted into ammonia?

Question 1

Keystone species:

are only found in aquatic habitats.

are always found at the top of the food chain.

are vital to the soil balance of an entire ecosystem.

are usually not the most abundant species in the ecosystem.

Question 2

All of the following traits are characteristic of the adaptations of prey EXCEPT:

producing toxins.

having the appearance of twigs or leaves.

warning coloration.

all of the above are characteristic prey adaptations

Question 3

The nitrogen cycle is one of the most important and complex of the biogeochemical cycles. Why is nitrogen important?

It’s an Ozone depleting gas

It’s an essential part of biological molecules such as proteins and nucleic acids (DNA)

It’s the most toxic element to living organisms

Nitrogen dilutes the oxygen in the atmosphere causing respiratory problems

Question 4

What important process might be severely impacted by colony collapse disorder?

nutrient cycling

pollination

symbiosis

predation

Question 5

What is the step in the nitrogen cycle in which gaseous nitrogen is converted into ammonia?

ossification

ammonification

assimilation

nitrogen fixation

Question 6

The mushrooms seen growing here gets its nutrition from:

Decomposing dead organic material that is the dead tree.

Photosynthesis.

Capturing earthworms and other soil invertebrates.

The living tree itself.

Question 7

How does the phosphorus cycle DIFFER from the carbon cycle?

There is little or no human impact on the phosphorus cycle.

Phosphorus is not a critical component of living organisms.

The hydrosphere plays a role in the phosphorus cycle.

The atmosphere does not contribute to the phosphorus cycle.

Question 8

Approximately what percentage of the atmosphere is CO2?

0.001%

0.04%

10%

30%

Question 9

How are temperate rain forests and the boreal forest similar?

Both have mild winters

Both are dominated by conifers

Both have tree species that are drought adapted

Both experience dense fogs

Question 10

The biomes that commonly have fire-adapted species and are known for supporting herds of grazing animals are:

temperate grassland and temperate deciduous forest.

temperate grassland and savanna.

chaparral and boreal forest.

boreal forest and temperate deciduous forest.

Question 11

Individuals within a population each have a unique combination of traits, which is known as:

Genetic variation.

Reproductive capacity.

Evolution.

Differential reproductive success.

Question 12

Which of the following biomes is NOT known for its wood and lumber production?

temperate rain forest

taiga

chaparral

temperate deciduous forest

Question 13

What is the main difference between short and tall grass prairies?

One is dominated by grasses and the other is dominated by forbs.

Tall grass prairies receive more rainfall than short grass prairies.

Short grass prairies occur in warmer latitudes than tall grass prairies.

Tall grass prairies typically have colder winters than short grass prairies.

Question 14

Which biome has considerable organic material in the soil, annual precipitation of 10-30 inches, and periodic wildfires to maintain the dominant vegetation?

temperate deciduous forest.

chaparral.

temperate grassland.

boreal forest.

Question 15

What biome is most likely to have the following temperature and rainfall profile?

savanna

boreal forest

tropical rainforest

temperate deciduous forests

Question 16

Which of the following is a biological control that is used to suppress wild fires in chaparral?

viral diseases

goats

introduced species

insect herbivores

Question 17

All of the following apply to estuaries EXCEPT:

There provide very valuable breeding grounds for commercially important fish and shellfish.

There is no salinity in estuarine ecosystems due to large supply of fresh water from a river.

Plants and algae that grow here have high tolerance for changing environmental conditions like salinity and light penetration.

These coastal ecosystems provide a barrier against the ocean during storms.

Question 18

The graph below is a record of the population size of reindeer on one of the Pribilof Islands off the coast of Alaska where they were introduced in 1911. If it is known that the availability of winter forage determines the carrying capacity for reindeer, what can be interpreted from this graph?

The population crashed due to overgrazing by the reindeer.

An environmental resistance factor like disease caused the population to decline somewhat.

Some reindeer were lost to predation by wolves.

Some reindeer emigrated to another island.

Question 19

The young age structure of urban areas can be attributed to:

high birth rates in urban areas

influx of young people from rural areas

high death rates in urban areas

the presence of more females than males in urban areas

Question 20

Which factors eventually cause birth rates to decline during a demographic transition?

Birth rates decline due to improved health care and modern medicines.

Birth rates decline due to increased education of women.

Birth rates decline due to increased contraceptive use.

All of these choices ultimately contribute to declining birth rates.

Question 21

According to the demographic transition model, an improving economy in a country is generally correlated with which of the following?

Increased birth rate and increased population growth rate

Increased death rate and decreased population growth rate

Decreased birth rate and increased population growth rate

Decreased birth rate and decreased population growth rate

Question 22

What change in human population growth is predicted by the United Nation’s population models?

Population will double by 2100.

Population will begin to level off by 2100.

Population will continue to grow exponentially.

Population will level off by 2525.

Question 23

What is probably the single most important factor affecting high total fertility rate in human populations?

Limited access to family planning services.

The low status of women in many societies.

The economic status of large families.

Cultural traditions.

Question 24

Who was the first scientist to sound the alarm about the growth of the human population and the ability of the earth to handle a large population of humans?

Charles Darwin

Paul Ehrlich

Thomas Malthus

Rachel Carson

Question 25

What do population ecologists study?

How animal communities form and interact

How groups of animals of the same species respond to their environment

The impact of humans on the environment

How ecosystems fit into the landscape