Principles of Ecology Chapter 18Which ingredient is not required in the process of carbon fixation to occur? Multiple choice question. PAR incorrect O2 Reason: Oxygen interferes with this process and makes it less effective than it otherwise would be. CO2

Which ingredient is not required in the process of carbon fixation to occur?

PAR

O2

CO2

O2

Which of the following is not one of the uses of forest biomass?

It is food for herbivores.

It is broken down into organic soil matter.

It is used as an energy source for photosynthesis.

It is food for detritivores.

It is used as an energy source for photosynthesis.

When studying ecosystems, Arthur Tansley realized the importance of considering organisms and their environment as a(n) blank system.

integrated

Which statement best fits the definition of primary production over some period of time?

production of new inorganic matter by autotrophs

production of new organic matter by autotrophs

production of new biomass by the heterotrophs

production of new organic matter by autotrophs

Secondary production is the rate of blank produced by heterotrophic consumers.

biomass

Select the statement that best describes the process of carbon fixation.

PAR converts CO2 into sugar and other biomass.

CO2 and O2 are converted into sugar and biomass.

PAR (photosynthetically active radiation) converts O2 into sugar and other biomass.

PAR converts CO2 into sugar and other biomass.

Which organism would directly use the biomass produced by forest vegetation?

oak tree

rabbit

Hyena

fox

rabbit

When determining an organism's trophic level, what group is used as the start of the transfer of energy?

detritivores

primary producers

secondary consumers

primary consumers

primary producers

An ecosystem is a biological community and all of the blank​.

biotic factors influencing it

relationships they have with other communities

living organisms within it

abiotic factors influencing it

abiotic factors influencing it

In which trophic level are the carnivores that feed upon herbivores placed?

first

second

third

fourth

third

The production of new organic matter, or biomass, by autotrophs in an ecosystem per unit area or volume during some period of time is known as blank

primary production

Identify the two key variables that are highly correlated with variation in terrestrial primary production.

moisture

temperature

soil pH

biodiversity of producers

moisture

temperature

The rate of biomass production by heterotrophic consumers is known as blank production.

secondary

Annual actual evapotranspiration (AET) is reported in what way?

millimeters of water evaporated and transpired per year

liters of water collected as runoff

liters of water stored per square meter of producers

grams of water stored per square meter

millimeters of water evaporated and transpired per year

Which variable helps explain the difference in terrestrial primary productivity within the same ecosystem?

elevation

levels of rainfall

soil fertility

temperature levels

soil fertility

What is the definition of a trophic level?

an organism's position within a food web

the amount of biomass generated by the autotrophs

the role an organism plays within the ecosystem

an organism's position within a food web

Which statement describes Liebig's (1840) Law of the Minimum?

All producers require a minimum amount of rainfall for growth.

Multiple nutrients control primary productivity.

A single nutrient controls primary productivity.

A single nutrient controls primary productivity.

In what trophic level are detritivores placed?

first

second

third

fourth

second

Identify the maximum increase in net primary productivity at the Shaver and Chapin study sites.

8%

23%

150%

300%

300%

Which environmental conditions would most likely produce the highest primary productivity?

warm and dry

warm and moist

acidic and wet

temperate and moist

warm and moist

What is annual actual evapotranspiration (AET)?

the total amount of water that evaporates and transpires during the course of a year

the total amount of water that is collected and retained by the producer's base during the course of a year

the total amount of water that transpires through the producer's base in a year

the total amount of water that evaporates and transpires during the course of a year

Which nutrient was determined to be a limiting factor in the biomass of phytoplankton?

total potassium

total iron

total phosphorus

available sulfur

total phosphorus

Which two soil nutrients play the greatest role in determining terrestrial primary productivity?

sodium

phosphorus

nitrogen

calcium

phosphorus

nitrogen

Which nutrient combination increased the phytoplankton biomass the most in the Experimental Lake Area study?

iron and carbon

sucrose and nitrate

sucrose, nitrate, and carbon

carbon, nitrate, and phosphate

carbon, nitrate, and phosphate

Liebig's Law of the Minimum helped scientists gain which perspective about primary productivity?

Rainfall levels will affect the rates of primary production.

Variation in soil fertility can affect the rates of primary production.

The same nutrient always limits primary productivity.

Variation in soil fertility can affect the rates of primary production.

Identify the minimum increase in net primary production at the Shaver and Chapin Alaska tundra study sites.

2%

23%

35%

300%

23%

The nutrient that is most often the limiting factor for marine ecosystems is blank

nitrogen

In addition to species diversity, what other facets are considered components of biological diversity?

Multiple select question.

climatic diversity

physiological diversity

ecosystem diversity

genetic diversity

elemental diversity

physiological diversity

ecosystem diversity

genetic diversity

What is the correct relationship between total phosphorus and plankton biomass when conditions are otherwise good for plankton growth?

Low total phosphorus is correlated with high phytoplankton biomass.

High total phosphorus is correlated with high phytoplankton biomass.

High total phosphorus is correlated with low phytoplankton biomass.

High total phosphorus is correlated with high phytoplankton biomass.

A collection of plants with similar physiological and anatomical characteristics that influence their seasonality, resources requirements, and life histories is known as a(n) blank​.

carbon fixation lineage

primary production troop

evolutionary NPP cluster

plant functional group

plant functional group

Which nutrients produce an increase in phytoplankton biomass in the Experimental Lake Area study area?

carbon

nitrate

sucrose

potassium

carbon

nitrate

sucrose

The primary production of a large lake has been increasing over time; a likely cause is blank​ the lake.

a drop in the average ambient air temperature above

an increase in the diversity of primary producers in

a decrease in the amount of runoff into the lake

the recent localized extinction of algae species from

an increase in the diversity of primary producers in

In which aquatic ecosystem is nitrogen the limiting nutrient for phytoplankton biomass?

marine

streams

Lake Victoria

Lake Michigan

marine

Species, genetic, physiological, anatomical, functional, and ecosystem diversity all are components of blank diversity.

bio

Which organism would most likely cause a trophic cascade?

field mouse

beech tree

grey wolf

rabbit

grey wolf

A plant functional group consists of plants with similar blank​ that influence their seasonality, resource requirements, and life histories.

geographic distributions

pollinators

physiological and anatomical characteristics

root structures in the same soil type

physiological and anatomical characteristics

Which abiotic factors stimulate plant production in a grassland ecosystem?

rainfall levels

carbon availability

soil fertility

types of grazing animals

rainfall levels

soil fertility

As the number of algal species increases in a lake, you would expect blank​ in primary production

no net change in

a decrease

an increase

strong fluctuations in

an increase

What mechanisms underly compensatory growth?

a decrease in water availability

a reduction in self-shading

lower rates of respiration

an increase in soil pH

a reduction in self-shading

lower rates of respiration

Which of the following factors are bottom-up controls of ecosystems?

physical factors

type of predators

chemical factors

physical factors

chemical factors

What happens to sunlight as it shines upon a forest?

Some is reflected from the forest canopy.

All of it is reflected by chlorophyll.

Some is converted into heat energy.

All of it is absorbed by chlorophyll.

Some is reflected from the forest canopy.

Some is converted into heat energy.

What are the effects of a trophic cascade?

a change in the prey abundance

a change in the productivity of a population

a change in the biomass

a depletion of soil nutrients

a change in the prey abundance

a change in the productivity of a population

a change in the biomass

Trophic dynamics is the transfer of energy from one part of an ecosystem to blank​.

another part of it

another part of the electromagnetic spectrum

the bottom trophic level

another ecosystem

another part of it

Which influences on grassland ecosystems are produced by grazing mammals? (More than one answer may be correct)

plant production

temperature

soil fertility

plant production

soil fertility

The results of a meta-analysis of tri-trophic studies about controls on the trophic structure showed that blank​.

both top-down and bottom-up effects were important

there were no cases where bottom-up effects were more important than top-down effects

sucking insects were not influenced by top-down effects

top-down effects were more important for most of the animal groups studied

both top-down and bottom-up effects were important

top-down effects were more important for most of the animal groups studied

What event would cause plants to undergo compensatory growth?

a decrease in atmospheric pressure

grazing by herbivores

an increase in the soil pH

an increase in the rainfall levels

grazing by herbivores

As primary production increases, the abundance of organisms blank​.

only increases at the level of predators

increases at all trophic levels

only increases at the primary level

is largely unaffected

increases at all trophic levels

Identify the bottom-up control.

average temperature

biodiversity of decomposers

type of predators

average temperature

What are the various forms of energy for consumers in a salt marsh?

inorganic solutes

detritus

phytoplankton

upland plants

detritus

phytoplankton

upland plants

What plant structure is responsible for absorbing solar energy?

bark on the trunk

mitochondria in surface leaf cells

starch in the leaves

chlorophyll in the leaves

chlorophyll in the leaves

When studying trophic dynamics, what is the key component that is being discussed?

nutrient levels

biodiversity of predators

transfer of energy

transfer of energy

The results of a meta-analysis of tri-trophic studies (including three tropic levels) about controls on the trophic structure discovered that in most cases blank​.

bottom-up and top-down effects were equally important

bottom-up effects were significantly stronger

top-down effects were significantly stronger

top-down effects were significantly stronger

Which of the following statements is true regarding the models displayed in the figure? Experimental and observational studies indicate blank​.

both models are equally supported

greater support for the ratio-dependent model

both models need to be rejected

greater support of the prey-dependent model

greater support for the ratio-dependent model

What is the main source of energy at the bottom trophic level of the salt marsh ecosystem?

zooplankton

detritus of salt marsh grass

phytoplankton

crabs

detritus of salt marsh grass