C 4.1

What is a population?

A group of individual organisms living and interacting in the same area.

What is carrying capacity?

The maximum population size an environment can support.

Why does carrying capacity exist?

Resources become limited → competition increases.

What are density‑independent factors?

Factors with the same effect regardless of population size.

What are density‑dependent factors?

Factors whose effects increase as population size increases.

What is a community?

Populations of different species living and interacting in the same area.

What are intraspecific relationships?

Interactions between individuals of the same species.

What is intraspecific competition?

Individuals of the same species competing for the same niche.

What is intraspecific cooperation?

A mutually beneficial relationship within a species.

What is herbivory?

Primary consumers eating primary producers.

What is predation?

One species kills and eats another.

What is interspecific competition?

Two species competing for the same resource.

What is mutualism?

Both species benefit from the interaction.

What is parasitism?

Parasite harms host but does not kill it.

What is pathogenicity?

A pathogen living inside a host and causing disease.

What are endemic species?

Species that occur naturally in an area.

What are alien species?

Species introduced to an area they don’t belong in; may become invasive.

What happens when prey population increases?

Predator population increases due to more food.

What happens when predator population increases?

Prey population decreases due to more predation.

What happens when prey decreases?

Predator population decreases due to less food.

What happens when predators decrease?

Prey population increases again.

What is top‑down control?

Higher trophic levels affecting lower ones.

What is bottom‑up control?

Lower trophic levels affecting higher ones.

What is allelopathy?

Release of toxic chemicals by an organism that harm other organisms.

What is a mesocosm and its purpose?

A small controlled ecosystem used to study populations, limiting factors, sustainability, and carrying capacity.

What do mesocosms require?

Light, nutrient cycling, waste breakdown.

What is a closed mesocosm?

No matter enters or leaves; only energy (light) moves in/out.

What is a limitation of mesocosms?

Not fully natural; small scale; organisms may behave differently.

What is a strength of mesocosms?

Controlled variables, replicable, allow long‑term observation.

Why are mesocosms advantageous?

They allow reliable, controlled experiments compared to natural ecosystems.