Ecosystem Ecology

What is the difference between an ecosystem and a community?

• Ecosystem consists only of living organisms, while community consists of living organisms and abiotic factors

• Ecosystem consists of living organisms and abiotic factors, while community consists only of living organisms

• Community includes abiotic factors, while ecosystem does not

• Ecosystem includes abiotic factors, while community does not

What is trophic structure?

• The interaction between living organisms and abiotic factors

• The geographical area covered by a biome

• The process of photosynthesis in plants

• The different feeding relationships in an ecosystem

What is the primary role of decomposers in an ecosystem?

• To provide energy to the producers

• To control the population of consumers

• To break down organic matter and feed on it

• To regulate the trophic levels

How does energy flow through ecosystems?

• All energy is converted to biomass at each trophic level

• Energy increases as it moves up trophic levels

• Energy decreases as it moves up trophic levels

• Energy is lost as heat when organisms are consumed

What is net primary productivity (NPP) a measure of?

• The organic matter available for heterotrophs after respiration

• The amount of light energy converted to chemical energy by autotrophs

• The energy used by autotrophs for respiration

• The total organic matter produced in an ecosystem

What is the role of secondary consumers in energy flow?

• To provide energy to primary producers

• To break down organic matter for decomposers

• To convert light energy into chemical energy

• To convert the energy of the food they eat into new biomass

What is ecological efficiency?

• The total energy available in an ecosystem

• The ratio of net productivity at one trophic level to the level below

• The percentage of energy lost as heat in an ecosystem

• The percentage of energy transferred between trophic levels

What does the pyramid of energy represent?

• The mass of biological materials at each trophic level

• The amount of energy flow at each trophic level over time

• The number of organisms at each trophic level

• The feeding relationships within an ecosystem

Why do food chains/webs usually include only 3-5 trophic levels?

• Because energy from top carnivores is insufficient to support another level

• Because secondary consumers consume all available energy

• Because energy increases at higher trophic levels

• Because primary producers are limited in number

What is the main reason for the inverted pyramid of biomass in some aquatic ecosystems?

• Limited availability of sunlight for photosynthesis

• Consumption of producers by consumers at a fast rate

• Low productivity of secondary consumers

• High energy conversion by primary producers