Ecology: Food Chains, Energy Flow, Cycles, and Populations

What is the difference between biotic and abiotic factors?

Biotic factors are alive (e.g., plants, animals), while abiotic factors are non-living (e.g., water, soil).

What is the hierarchy of ecological organization?

Organism → Population → Community → Ecosystem → Biosphere

What happens when an organism is removed from a food chain?

Its predators lose a food source, and its prey may thrive and increase in population.

What is the role of a producer in a food chain?

Producers make their own food, usually through photosynthesis (e.g., grass).

What is a primary consumer?

A primary consumer eats producers (e.g., a rabbit).

What does a secondary consumer eat?

A secondary consumer eats primary consumers (e.g., a snake eating a mouse).

What is a tertiary consumer?

A tertiary consumer eats secondary consumers (e.g., a hawk eating a snake).

What is the role of decomposers in an ecosystem?

Decomposers break down dead organisms and waste (e.g., fungi and bacteria).

What is an autotroph?

An organism that makes its own food.

What is a heterotroph?

An organism that obtains energy by consuming other organisms or organic matter.

What is the energy flow pathway in an ecosystem?

Sun → Producer → Primary Consumer → Secondary Consumer → Tertiary Consumer

How is energy used in an ecosystem?

Energy is used for movement, growth, reproduction, cellular respiration, and maintaining life processes.

What is the average energy transfer efficiency between trophic levels?

Approximately 10% of the energy available at one trophic level is transferred to the next level.

What does an energy pyramid measure?

The energy available at each trophic level, usually measured in kJ or kcal per unit area per unit time.

What is a biomass pyramid?

A biomass pyramid measures the total mass of living material at each trophic level, usually in grams per square meter.

What is a pyramid of numbers?

A pyramid of numbers measures the number of individual organisms at each trophic level.

What are the main reservoirs for the carbon cycle?

Atmosphere, oceans, rocks, and living matter.

What key processes are involved in the water cycle?

Evaporation, condensation, precipitation, and transpiration.

What is mutualism?

A symbiotic relationship where both organisms benefit (e.g., bees pollinating flowers).

What is parasitism?

A symbiotic relationship where one organism benefits while the host is harmed (e.g., a tick feeding on a mammal).

What is carrying capacity?

The maximum population size an environment can sustainably support under current conditions.

What is primary succession?

Primary succession occurs in an area where no developed soil is present, such as newly formed volcanic rock.

What is a biome?

A large ecological region characterized by its climate and typical vegetation, along with its associated animal communities.