ESS

The main difference between 'S' and 'J' population growth curves is that

'J' curves reach no stable maximum.

Which productivity equation is correct?

(gross secondary productivity) = (food consumed) - (energy in feces)

Which is most likely to be an internal density dependent factor regulating a population of herbivores?

An increased fertility rate as herbivores decrease in number

Which statement is correct? A. A food chain can never have more than four members. B. Ecosystems that have a high productivity often also show high biodiversity. C. One ecosystem can never contain another within it. D. Pioneer communities usually contain more plant species than climax communities

Ecosystems that have a high productivity often also show high biodiversity.

Which statement is correct A. Elephants are K-strategists because they have a low population growth rate. B. r-strategists tend to reproduce late and have few offspring. C. The population size of a species is only genetically controlled. D. All plants are K-strategists because they have limited ability to compete.

Elephants are K-strategists because they have a low population growth rate.

As disease spreads through a population, numbers fall. As the result of a reduction in contact between individuals, the rate of spread of the disease is reduced. This is followed by a recovery in numbers. This is an example of

negative feedback

The energy available to the tertiary consumers (top carnivores) in a particular ecosystem is 10 kJ m-2 y-1. How much energy (in kJ m-2 y-1) is likely to be passed on by the producers to the primary consumers?

1000

If the producer biomass in an ecosystem is 150 kg per hectare (kg ha-1), what is the approximate primary consumer (herbivore) biomass (in kg ha-1) that might be expected in the same ecosystem?

15

If the producer biomass in an ecosystem is 300 kg ha-1, what is the approximate secondary consumer biomass (kg ha-1) likely to be in the same ecosystem?

3

Which of the following is an example of mutualism?

An insect pollinating an orchid flower

Which statement best describes the niche of a species in its habitat?

The biotic and abiotic components it requires

Which statement best describes a climax community? A. The end-point of ecological succession. B. A group of organisms in a community at the same trophic level in a food chain. C. The minimum number of a species that can be supported by a given environment. D. A community at an early stage of ecological succession.

The end-point of ecological succession.

Which of the following is the best definition of a population? A. The number of individuals of a given species B. The number of individuals of the same species in a given area C. The number of species in a given area D. The number of individuals in a given area

The number of individuals of the same species in a given area

biodiversity.

The number of species within a specific habitat.

Which statement most correctly describes K-strategist organisms?

They reach adulthood slowly and have few young.

Which of the following is a characteristic of K-selected organisms?

They usually have a high degree of parental care of young.

Which of the following are examples of mutualism? I. Bacteria fixing nitrogen in the roots of plants II. The pollination relationship between flowering plants and insects III. Lions hunting zebras IV. Mosquitos spreading malaria

I and II only

Ecological succession generally involves I. a decrease in the entropy of an ecosystem. II. loss of communities through competition. III. an increase in the ratio of organic to inorganic storages

I, II and III

Which of the following combinations is typical of r-selected organisms? I. A high number of offspring II. A tendency to be associated with temporary habitats III. Completion of the life-cycle in a relatively short period IV. A low number of offspring V. A high level of parental care VI. A rapid rate of growth

I, II, III and VI only

If a tropical river were to be accidentally polluted with a pesticide, where is the highest concentrations of the pollutant most likely to be found after several years?

In crocodiles and other carnivores

Which statement best explains why the net productivity of a climax community approaches zero as a result of succession?

Increased length of food chains >>>>increase in respiration.

When a population exceeds the carrying capacity of the environment that supports it, which process often restores the equilibrium?

Negative feedback

If the rates of photosynthesis and respiration (in a plant) were exactly equal, which of the following would be true?

Net Productivity would be zero

Which are producers?

O

A biome is

a collection of ecosystems sharing similar climatic conditions.

The carrying capacity of an environment for a given species

can only be exceeded with unsustainable use of resources.

An input to photosynthesis is

carbon dioxide

The following are processes occurring in mineral cycles:

conversion of nitrites to nitrates

The net productivity for the consumer community is

e − g − j.

Food chains seldom have more than four members because

energy is lost as it moves along a food chain and little remains at the top carnivore level

Compared to a pioneer community, a climax community would have

higher gross productivity.

An r-strategist generally

is small and short-lived

Which unit is the most appropriate to express the gross primary productivity of an ecosystem?

kg m-2

The main deserts of the world are found at

latitudes between the temperate and tropical forests.

Nitrogen is removed from the atmosphere by

lightning

Net primary productivity is the total biomass

made from inorganic matter that remains after respiratory losses.

Nitrogen is returned to the atmosphere by

nitrifying bacteria

A diversity index of an ecosystem typically takes into account

number of species and their abundance.

The largest store of carbon on earth is in

rocks and soils.

A community is composed of

several populations.

Major climatic factors affecting ecosystems are

temperature and precipitation.

In a normal terrestrial ecosystem, most nutrients

tend to be recycled.

Biomass is best defined as

the dry weight of organic material.

An ecological niche is

the role a species has in an ecosystem.

In a mature forest, the trees are eaten by small primary consumers which are then eaten by much larger secondary consumers. Which of the following pyramids best represent this ecosystem?

Pyramid of #- 2-3-1 Pyramid of biomass- 1-2-3

What is a biome?

A collection of ecosystems sharing similar climatic conditions

What is a biome?

A collection of ecosystems sharing similar climatic conditions.

Which of the following is most likely to be a parasite?

A fungus in the living tissues of a tree

What is a group of organisms of the same species living in the same area at the same time known as?

A population

Which of the following might show primary succession?

A rock surface exposed by a retreating glacier

Which statement relating to trophic levels is true?

A single species may occupy more than two different trophic levels.

What information would you need to estimate the gross productivity of a population of consumers over a period of time?

Biomass of food eaten and biomass of feces produced only

Secondary Productivity (SP) is

C - (R + U + F).

Which of the following statements about food chains is true?

Carnivores are never at the second trophic level.

Which of the following correctly represents the energy transformations involved in respiration and photosynthesis?

Chemical to heat Light to chemical

How is the net productivity of the producers in an ecosystem defined?

Energy fixed by biomass per unit time minus respiratory losses

Modern commercial agricultural practices tend to

Lower Reproduce Create

Which form of natural capital absorbs carbon dioxide?

Producers

Which term could not be applied to an organism feeding on the biomass of a producer?

Secondary consumer

Which is least likely to be an example of mutualism?

Small plants of another species attached to the surface of a tree

Consider these statements concerning the flow of energy through ecosystems: Statement 1: The amount of energy that is available to living things decreases as it is transformed and passed along food chains. Statement 2: As energy is transformed along food chains, no energy is destroyed. Which is a correct evaluation of these statements?

1- Demonstrates the second law of thermodynamics 2- Demonstrates the first law of thermodynamics

In a survey of an antelope population, 80 antelope were marked and released. Two weeks later a second sample was captured, of which 16 antelope were found unmarked and 4 were marked. What would be the estimated population size?

400

The frequency of bush fires increases as the abundance of an inflammable plant species increases. At the same time, the increased frequency of fires leads to a decrease in the population of certain animals. In what way(s) is the fire acting in this example?

As a density-dependent factor for plants and a density-independent factor for animals

Which of the following is an internal, density dependent factor that could control the size of a rabbit population?

Competition for food between rabbits

Which process involved in the cycling of matter could be described as a transformation process requiring the input of solar radiation?

Conversion of nitrates into organic molecules containing nitrogen

An animal population is given 50 kg of feed per day, of which 40 kg is consumed. 20 kg of feed per day is used in respiration and 15 kg of feces per day is released. Which of the following are the correct values for gross and net productivity?

Gross- 25 Net- 5

As succession approaches a climax, which changes are likely to occur in an ecosystem?

Gross- Increase Decrease Net- Decrease

Which process reduces storages of soil nutrients?

Heavy rainfall

Which of the following are found at the second trophic level in a food chain? A. Carnivores B. Herbivores C. Secondary consumers D. Primary producers

Herbivores

The main factors that determine the type of biome found are I. temperature. II. precipitation. III. soil type. IV. wind direction.

I and II only

What information is necessary to calculate the net primary productivity of an ecosystem? I. The biomass produced by photosynthesis per unit area per unit time. II. The biomass lost by the plant by respiration per unit area per unit time. III. The biomass gained by heterotrophic organisms per unit area per unit time. IV. The biomass potentially available to consumers per unit area per unit time.

I and II only

Which statement(s) correctly describe the relative productivity of different biomes? I. The productivity of biomes always decreases with increasing distance from the equator. II. The productivity of biomes is directly proportional to the amount of solar energy they receive. III. The productivity of biomes is related to the prevailing climatic conditions at their latitude.

III only

If toxic materials were to be released into a coral reef ecosystem, in which part of the ecosystem would you expect them to accumulate to the greatest extent?

In the tissues of large carnivorous fish such as sharks

Which interaction would benefit both organisms in a relationship?

Mutualism

Which combination of abiotic factors is typical of the tropical forest biome?

Narrow range of temperatures and high rainfall

Which statement about trophic levels is correct? A. The biomass per unit area usually increases with each trophic level. B. A trophic level defines the feeding rate of an organism in a food chain. C. No organism can occupy more than one trophic level in a food web. D. Naturally occurring terrestrial food chains rarely have more than five trophic levels.

Naturally occurring terrestrial food chains rarely have more than five trophic levels.

Which statement about the storage of nitrogen in ecosystems is correct?

Nitrogen is stored in the animal biomass of an ecosystem mainly in the form of protein.

In which way do "S" and "J" population curves differ from one another?

Only S curves show negative feedback as the population stabilizes.

Which of the following correctly describes the components of a population, community, ecosystem and habitat?

Population- Biotic only Community- Biotic only Ecosystem- Biotic and abiotic Habitat- Biotic and abiotic

Which statement is correct? A. Secondary consumers can be abiotic or biotic components of ecosystems. B. Temperature, soil pH and decomposers are abiotic components of soil ecosystems. C. Primary consumers are always biotic components of ecosystems. D. Bacteria, turbidity and plankton are biotic components of marine ecosystems.

Primary consumers are always biotic components of ecosystems.

Which organisms have a net output of oxygen?

Producers

Which of the following can generally be deduced from the shape of the survivorship curves for a given species? A. Number of births per year B. Maximum rate of population growth C. Carrying capacity for a given population D. Relative amount of parental care and investment per individual offspring

Relative amount of parental care and investment per individual offspring

Which statement describes secondary productivity? A. The quantity of solar energy fixed by photosynthesis by green plants B. The biomass gained by heterotrophic organisms through feeding and absorption C. The process of capturing sunlight to make sugars and other organic compounds D. The quantity of biomass potentially available to consumers in an ecosystem

The biomass gained by heterotrophic organisms through feeding and absorption

Which statement about a food chain is correct? A. The top carnivore is the species most vulnerable to extinction. B. The system is very efficient with low energy loss. C. Approximately 10 % of energy is lost in every transfer. D. The tertiary consumers will always have the largest number of individuals.

The top carnivore is the species most vulnerable to extinction.

Which of the following is characteristic of r-selected organisms?

They are typical of pioneer communities.

Which statement about energy transformations is correct?

When an organism grows its entropy usually decreases.

An increase in parasitism, causing reduced survival in a host population as that population increases in size, is an example of

a density dependent factor.

Compared to pioneer communities, climax communities usually have

a higher gross productivity.

Which list contains only abiotic components of an ecosystem?

air, water, rock

A parasite, infecting the organs of its host, spreads from host to host more rapidly when the host population, in a given area, is higher. Assuming infection with the parasite reduces fertility, this would be an example of control of the host population through

an external, density dependent factor.

Net Primary Production is the amount of energy

inecosystem by photosynthesis, minus the losses due to respiration

Net Primary Productivity (NPP) is the total amount of energy fixed in an ecosystem by

photosynthesis minus the amount used by producers in respiration.

Two herbivorous animals are part of the same community. One of them is prey to many predators and the other has no natural predator. They are

primary consumers and occupy different ecological niches.

In the process of succession, earlier communities disappear because

they are displaced through competition.

If a lake is sprayed with a non-biodegradable insecticide to kill mosquitoes, after a few years the highest concentrations of insecticide are most likely to be found in the

tissues of predatory fish and fish-eating birds.

Which list includes three abiotic factors that affect aquatic plants?

water temperature, oxygen concentration, light intensity

An ecological niche is

where a species lives and what it does in its environment.