Module 3: Biological Diversity Practice Flashcards

A set of vocabulary-style flashcards covering the key concepts, case studies, and definitions from Module 3: Biological Diversity.

Biodiversity

The variety of different species of plants and animals, which is important to balance the Earth’s ecosystems.

Selection pressures

External agents which affect an organism’s ability to survive in a given environment and can be negative (decrease the occurrence of a trait) or positive (increase the proportion of a trait).

Biotic factors

The living things that shape an environment and exist at different trophic levels, including producers, consumers, and decomposers.

Producers

Plants and other photosynthetic or chemosynthetic organisms.

Consumers

Animals that depend on producers for food.

Decomposers

Fungi and microbes that break down material from dead or decaying organisms into simpler forms, which can be reused.

Predation

A biotic interaction where one animal kills another for food (predator/prey).

Competition

An interaction where organisms, often of the same species, compete over the same resource, space, or mate.

Parasitism

A symbiotic relationship where one organism benefits at the expense of another by harming or killing them.

Commensalism

A symbiotic relationship where one organism benefits while the other is neither harmed nor benefits.

Mutualism

A symbiotic relationship where both organisms benefit from the relationship.

Abiotic factors

Non-living components of an ecosystem such as temperature, humidity, wind speed, salinity, soil pH, light intensity, and oxygen availability.

Viscosity

A measure of a fluid's resistance to flow; air has low viscosity while water has higher viscosity, requiring aquatic organisms to be streamlined.

Buoyancy

A property of water that supports the weight of organisms, meaning aquatic organisms often do not need supportive structures like skeletons.

$$Bufo \text{ } marinus$$

The scientific name for the cane toad, introduced into Australia in $1935$ from South America to control the cane beetle.

Microevolution

Small-scale evolutionary changes within a population, such as the documented changes in cane toad leg length and red-bellied black snake head size within a human lifespan.

Prickly pear

An invasive plant introduced in the $1830s$ that covered $24,250,000$ hectares by the $1920s$ before being controlled by biological means.

$Cactoblastis$ moth

The natural predator from South America used as successful biological control to decrease prickly pear populations starting in $1925$.

Adaptation

A biological response to a selective pressure; the process by which a population over several generations changes to fit a particular environment.

Structural Adaptations

Adaptations that involve some part of the organism’s body, such as teeth shape, body size, camouflage, or fur cover.

Physiological Adaptations

Internal systemic responses to external stimuli to help maintain homeostasis, such as sweating, dilating blood vessels, or tolerance to poison.

Behavioural Adaptations

Actions an organism performs to survive, such as seeking shelter, living in groups, or tool use; these can be learned within a single lifespan.

Charles Darwin

An English naturalist ($1809$-$1882$) who developed the theory of Evolution by natural selection based on observations from the HMS Beagle voyage.

Convergent Evolution

The process by which different species isolated in different countries adapt to become similar because they are exposed to similar selection pressures.

Theory of Evolution by Natural Selection

A theory posed by Darwin and Wallace describing 'survival of the fittest' based on inherited variation, competition, selection, and adaptation.

Punctuated Equilibrium

An evolutionary theory that is different from the gradual process of natural selection, describing stable periods interrupted by rapid change.