Populations and Communities

Flashcards covering key vocabulary and concepts related to populations, communities, and ecosystems.

Population

An interacting group of organisms of the same species that inhabit the same geographical area and are capable of breeding with one another (no reproductive isolation).

Population Growth Curve

Stable populations demonstrate a sigmoidal (S-shaped) population growth curve comprising three key stages: Exponential Growth Phase, Transitional Phase, and Plateau Phase.

Exponential Growth Phase

Rapid population growth due to an abundance of resources, represented by a J-curve.

Transitional Phase

The stage in a population growth curve where growth slows due to environmental resistance.

Plateau Phase

The stage in a population growth curve where the population stays stable at the carrying capacity.

Carrying Capacity

The maximum number of individuals of any species that an environment can support.

Density-Dependent Factors

Factors that impact population size based on population density, such as predation, access to habitats, nutrient supply, disease, and accumulation of wastes.

Intraspecific Interactions

Interactions that occur between members of the same species, including cooperation and competition.

Predator-Prey Relationship

A relationship where a predator hunts and feeds on another organism (the prey), impacting both populations' sizes.

Community

A group of populations living together and interacting with each other within a given area; the biotic component of ecosystems.

Interspecific Relationships

Relationships between different species within a community, including feeding relationships, interspecific competition, and symbiosis.

Herbivory

The act of eating only plant matter by primary consumers.

Predation

A feeding pattern where a predator hunts and feeds on another organism (prey).

Mutualism

A symbiotic relationship where both species benefit from the interaction.

Commensalism

A symbiotic relationship where one species benefits, and the other is unaffected.

Parasitism

A symbiotic relationship where one species benefits, and the other is harmed.

Pathogenicity

Infectious microorganisms living inside or on the surface of a host organism and causing disease.

Antibiotics

Biological compounds released by certain organisms to kill or impede the growth of bacterial pathogens.

Interspecific Competition

Competition that occurs when different species compete for access to a limited resource.

Invasive Species

Alien species that have a detrimental effect upon existing food chains.

Top-Down Control

Population control exerted by a higher trophic level, inducing oscillating effects.

Bottom-Up Control

Population control exerted by a lower trophic level, reducing all higher levels.

Habitat

The physical environment in which a community, species, population, or organism normally lives; the abiotic components of an ecosystem.