Grade 11 Biology: Biodiversity & Ecosystem Health

Vocabulary terms and definitions from Grade 11 Biology Chapter 1 regarding classification, ecosystems, biomes, and human impacts on biodiversity.

Nomenclature

The system of rules used to name things.

Taxonomy

The system of naming organisms.

Systematics

The system of classifying organisms based on their evolutionary relationship.

Binomial name

A unique scientific name for a species consisting of the Genus (capitalized and italicized) and the species (lowercase and italicized).

Hierarchical Classification

Naming organisms using nested levels ranging from broad to general: Domain > Kingdom > Phylum > Class > Order > Family > Genus > Species.

Phylogenetic Trees

Branching diagrams that show the evolutionary history of organisms.

Phylogeny

The evolutionary history of a species or group of organisms.

Taxon (Taxa)

The taxonomic unit at any level of the hierarchical classification system.

Sister taxa

Two or more taxa that are next to each other on a phylogenetic tree, indicating they are closely related.

Clade

A group of taxa that share a common ancestor.

In group

A group of interest that is usually the focus of an evolutionary study.

Out group

One or more taxa that are distantly related to the primary group of interest (in group).

Character

A specific characteristic used in cladistics, such as a wing or a tail.

State

A particular property of a character, such as the color of a tail or the shape of a wing.

Analogous traits

Traits that appear similar but actually evolved independently through convergent evolution.

Convergent evolution

A process where natural selection produces a similar trait from different starting points.

Homologous traits

Traits that are similar due to true shared ancestry, descended from the same trait in a common ancestor.

Dichotomous Keys

A two-part system used to classify living things which requires only 2 choices at each node to proceed to the next branch.

Biomes

Broad geographical areas with similar biological communities, primarily determined by temperature and precipitation.

Evapotranspiration

The amount of water plants lose due to climate conditions.

Freshwater Biome

A body of water with a salt concentration less than $1\%$, including ponds, lakes, streams, rivers, and wetlands.

Littoral Zone

The region of a lake or pond near the shore with varying temperatures that supports diverse organisms like algae, snails, and amphibians.

Limnetic Zone

The open water of a lake or pond near the surface that supports plankton and some fish.

Profundal Zone

The bottom of a lake that is cold, dense, and has little to no light, resulting in minimal plant life.

Wetlands

Standing waters like marshes, swamps, and bogs which possess high species diversity.

Hydrophytes

Plants supported by wetlands, such as lilies, cattails, and black spruce.

Tropical Forests

Forests near the equator with constant $12$-hour light cycles, temperatures between $20-25^{\circ}\text{C}$, and more than $200\,\text{cm/year}$ of rainfall.

Temperate Forests

Forests at $25-50^{\circ}$ latitudes with fertile soil and trees that lose their leaves annually.

Boreal (Taiga) Forests

The largest terrestrial ecosystem, characterized by snow precipitation, nutrient-poor soil, and cold-tolerant evergreens like pine and spruce.

Intertidal Zone

The marine zone where land and ocean meet, often organized vertically in rocky coastal regions.

Pelagic Zone

The open ocean at the surface which supports seaweed, sharks, whales, and plankton.

Benthic Zone

The marine zone below the pelagic but above the abyssal zone, characterized by very little light and cold temperatures.

Abyssal Zone

The deep ocean with no light, high pressure, and high oxygen levels where chemosynthetic bacteria act as autotrophs near hydrothermal vents.

Coral Reefs

Ecosystems found in warm, shallow ocean water where the dominant organism is coral made of animal polyps and algae.

Estuaries

Ecosystems found where freshwater streams or rivers meet the mouth of the ocean.

Desert

Any ecosystem that receives less than $50\,\text{cm/year}$ of rainfall.

Savanna

Grasslands in warm/hot climates with annual rainfall of $50-130\,\text{cm/year}$ concentrated in $6-8$ months.

Temperate Grassland

Ecosystems with hot summers and cold winters ($-40^{\circ}\text{C}$ to $+40^{\circ}\text{C}$) that include prairies (tall grasses) and steppes (short grasses).

Arctic Tundra

A biome with temperatures between $-40^{\circ}\text{C}$ and $+12^{\circ}\text{C}$, low precipitation ($15-25\,\text{cm/year}$), and permafrost.

Permafrost

Permanently frozen subsoil found in the tundra.

Alpine Tundra

Tundra found at high altitude mountains globally, supporting grasses, dwarf trees, and shrubs.

Niche

The combination of a species' physical habitat and its ecological role, determined by abiotic and biotic factors.

Fundamental Niche

The theoretical range in which a species could exist based on climate, food, and shelter.

Realized Niche

The actual range in which a species does exist, often limited by interactions with other species.

Competition

An interaction where two species compete for the same resource, resulting in a lose-lose situation where neither benefits.

Intraspecific Competition

Competition occurring between individuals belonging to the same species.

Interspecific Competition

Competition occurring between individuals belonging to different species.

Competitive Exclusion

A situation where interspecific competition is so intense that one species completely excludes another from an area.

Resource Partitioning

A process where species evolve differences in traits, such as feeding strategies or activity times, to reduce competition.

Predation

An interaction where one species (predator) consumes another (prey).

Parasites

Organisms that live on or in another species (host) to gain nutrition directly from their tissues without typically killing them.

Herbivory

The consumption of plants by animals.

Facilitation

An interaction where two species cooperate to prey on or attack a third species, such as fungi and beetles attacking pine trees.

Mutualism

A species interaction where both participating species benefit.

Symbiosis

A relationship where two mutualists completely depend on each other for survival.

Obligate mutualism

A type of mutualism where one or both species cannot survive without the other.

Facultative mutualism

A type of mutualism where one or both species can survive without the other if necessary.

Commensalism

An interaction where one species benefits while the other is unaffected.

Disturbances

Events like storms, earthquakes, or human activities that produce severe physical impacts on a habitat.

Pulse disturbances

Short-term, immediate disturbances such as windstorms, floods, fires, or disease outbreaks.

Press disturbances

Long-term, persistent disturbances such as climate change or geological processes.

Disturbance Regime

The specific type, frequency, and severity of disturbances in a given habitat.

Succession

The process of community response and recovery in a new habitat created by a disturbance.

Primary succession

Succession that occurs when all life was wiped out, starting from bare rock or scratch.

Secondary succession

Succession that occurs when only some life was wiped out, leaving soil and seeds intact.

Pioneer species

The first organisms to re-colonize an area after a disturbance, often starting with lichens.

Climax Community

A stable community that has reached equilibrium with minimal species change.

Intermediate disturbance hypothesis (IDH)

The theory that intermediate levels of disturbance support the greatest species diversity.

Monoculture Farming

The practice of growing a single crop, plant, or livestock animal in a farming area, leading to decreased soil quality and lower diversity.

Polyculture Farming

The practice of growing multiple crops or animals together, providing higher yields and biological control against pests.

Habitat loss

The process where a habitat becomes unable to support its historically native species.

Habitat Destruction

A level of habitat loss where none of the native species can be supported by current land usage.

Habitat Degradation

A level of habitat loss where current quality only supports some native species while many others are excluded.

Habitat Fragmentation

The process where human activities like road building interrupt a species' range, causing populations to become smaller and isolated.

Land Use Change

The process of changing the historical usage of land for human economic or urbanization purposes.

Wildlife corridors

Strips of natural habitat designed to connect wild populations otherwise disconnected by farming, roads, or dams.

Conservation

The planned management of natural resources to prevent their exploitation and destruction.

Inside-habitat conservation

Conservation efforts occurring within natural settings, such as land management and protection.

Outside-habitat conservation

Conservation efforts occurring outside natural settings, including zoos, botanical gardens, and seed banks.

Keystone Species

A single species whose loss would greatly affect the entire ecosystem balance and cannot be functionally replaced.

Umbrella Species

A species with a large geographic range whose protection often determines the size of protected areas.

Foundation Species

Species that create or maintain a habitat, such as coral reefs and many tree species.

Ecosystem Engineers

Species with the ability to change, create, or maintain their habitat, such as beavers or corals.

Indicator Species

Species sensitive to environmental changes that signal the health of the ecosystem.

Flagship Species

Charismatic mascot species used to gain human support for conservation efforts, such as the giant panda.

Ecological Restoration

Human assistance in the recovery of an ecosystem that has been damaged, degraded, or destroyed.