Topic 2.1: Individuals, Populations, Communities, and Ecosystems

What is the biosphere?

An ecological system composed of individuals, populations, communities, and ecosystems where life exists.

Define a species.

A group of organisms that can interbreed and produce fertile offspring, identified by a two-part name: genus and species.

What tools can be used to identify species?

Dichotomous keys, comparison of specimens, DNA surveys, apps like PlantNet and Naturalist.

What is a clade?

A clade illustrates evolutionary relationships where all members of a taxonomic group evolved from a common ancestor.

What defines a population in ecology?

A group of organisms of the same species living in the same area at the same time capable of interbreeding.

What is the difference between a community and a habitat?

A community is a collection of interacting populations, while a habitat is the location where a community, species, or population resides.

What is an ecosystem?

An ecosystem is a community and the physical environment where it interacts, functioning as an open system for energy and matter.

What are abiotic and biotic factors?

Abiotic factors are non-living physical elements that influence organisms, while biotic factors refer to the living components of an ecosystem.

Name types of population interactions in ecosystems.

Herbivory, predation, parasitism, mutualism, disease, and competition.

What is an ecological niche?

The particular set of abiotic and biotic conditions and resources upon which an organism depends.

What is the fundamental niche?

The full range of conditions and resources in which a species could survive and reproduce.

What is carrying capacity?

The average size of a population determined by competition for limited resources, which can fluctuate over time.

What are density-dependent factors?

Factors that are more influential as population density increases, such as competition, predation risk, and disease transmission.

What are keystone species?

Species that have a significant impact on community structure, with a heightened risk of ecosystem collapse if removed.

What distinguishes r-strategists from K-strategists?

r-strategists produce many offspring with little parental care, while K-strategists produce fewer offspring with more parental care.