Module 3: Biological Diversity - 3.1 Effects of the Environment on Organisms

Vocabulary flashcards covering the fundamental concepts of biological diversity, ecosystem types, selection pressures, and Australian ecology based on the lecture notes.

Biodiversity

The variety of life that is important to balance the Earth’s ecosystems and can be affected by natural selective pressures or human impact.

Population

A group of the same species living in the same area.

Community

A group of different species living in the same area.

Ecosystem

A biological community of interacting organisms and their physical environment.

Biome

A community of organisms that live in a distinct region defined by its climate and dominant vegetation, where ecosystems are considered subunits.

Biotic factors

Living things within an ecosystem that influence species diversity.

Abiotic factors

Non-living components of an ecosystem such as temperature, rainfall, and soil composition.

Selection pressures

External factors that occur when organisms in an environment must compete for resources due to environmental changes, increasing natural selection.

Habitat

The specific place where an organism lives.

Species

A group of organisms of similar appearance within a population whose members can interbreed and produce fertile offspring.

Species diversity

A measure of the diversity of species within an ecological community.

Keystone species

An organism that helps define an entire ecosystem; without it, the ecosystem would be dramatically different or cease to exist.

Desert

A terrestrial ecosystem with annual rainfall $< 250\,mm$, high day temperatures ($\approx 40^\circ C$), and low night temperatures ($\approx 0^\circ C$).

Grassland

A terrestrial ecosystem with annual rainfall between $250-750\,mm$ and temperatures that can be high or mild.

Shrubland

A terrestrial ecosystem with high temperatures and annual rainfall between $200-400\,mm$, featuring mallee trees and mulga.

Woodland

An ecosystem with annual rainfall between $400-750\,mm$, mild to high temperatures, and a canopy cover of $10-30\%$. Cantor canopy cover is $10-30\%$.

Temperate forest

An ecosystem with mild temperatures, annual rainfall $> 750\,mm$, and canopy cover of $30-70\%$. Cantor canopy cover is $30-70\%$.

Tropical rainforest

An ecosystem with dense canopy cover ($70-100\%$), humidity, and annual rainfall $> 1500\,mm$, where distinct layers or strata develop.

Adaptations

Random variations due to genetics or mutations that make an individual better suited to survive in a changed environment.

Distribution

A description of where a specific species is found within an environment.

Abundance

A measurement of how many individuals of a species live in a particular ecosystem.

Ecology

The study of the interrelationships of organisms and their environment.

Viscosity (Aquatic)

An abiotic factor characterizing aquatic environments as having high viscosity compared to air.

Buoyancy (Aquatic)

An abiotic factor in which water supports the body weight of organisms.

Cane toads

An example of a population in Australia used to investigate changes due to selection pressures over time.

Prickly pear

An example species used to investigate changes in distribution in Australia due to selection pressures.