Ch. 19 + Ch. 20 (Speciation + Ecology) Vocab

Species

Individuals capable of interbreeding freely with each other but not with members of another species.

Speciation

The process of forming new species.

Sympatric Speciation

Origin of a new species in populations that overlap geographically.

Allopatric Speciation

Origin of a new species in populations that are separated geographically.

Reproductive Isolating Mechanisms

Different reasons why individuals would no longer be able to reproduce.

Spatial Isolation

A prezygotic isolating mechanism in which species select different places to live and reproduce.

Behavioral Isolation

A prezygotic isolating mechanism in which species differ in mating behaviors such as visual cues or vocalization.

Temporal Isolation

A prezygotic isolating mechanism in which species reproduce during different times so mating periods do not overlap.

Mechanical Isolation

A prezygotic isolating mechanism in which the reproductive organs of species are incompatible due to size and shape.

Gametic Isolation

A prezygotic isolating mechanism in which the sperm and egg are incompatible.

Post-Zygotic

Isolating mechanisms in which zygote form but embryo does not survive or survive and are sterile.

Extinction

Death of all members of a species.

Mass Extinction

Episode during which large numbers of a species become extinct.

Ecology

Study of the interactions among organisms and their physical environment.

Population

All the members of one species inhibiting an area.

Community

All the different species interacting in one area.

Ecosystem

All the living and nonliving components in one habitat.

Biome

One of the world’s major ecoystems.

Biosphere

Part of Earth occupied by living organisms.

Biotic

Pertaining to living organisms.

Abiotic

Pertaining to non-living.

Autotrophs

Organisms that have the ability to make their own food.

Heterotrophs

Organisms that cannot make their own food and therefore must depend on an outside source for nutrients.

Producers

Organisms that change energy into food.

Consumers

Organisms that eat producers or other consumers.

Decomposers

Organisms absorb nutrients from nonliving organic material such as corpses, fallen plant material, and the wastes of living organisms, and convert them into organic molecules.

Symbiotic Relationships

Ecological interactions that involve two different species that live together in direct contact.

Commensalism

A symbiotic relationship in which one organism benefits but the other is neither helped nor harmed.

Mutualism

A symbiotic relationship in which both participants benefit.

Parasitism

A symbiotic relationship in which the symbiont benefits at the expense of the host.

Food Chains

Pathway along which food is transmitted from trophic level to trophic level, beginning with producers

Food Webs

Elaborate and interconnected food chains.

Trophic Level

Any of the several levels of a food chain, whose species are based on their main nutritional source.

Biomass

The weight of a living organism.

Dry-Weight

The weight of an organism without water.

10% Rule

A rule that states only about ten percent of usable energy stored in a trophic level is passed from one level to the next.

Joules

Measure of energy.

Grazing Food Webs

A type of food web that begin with producers.

Detrital Food Webs

A type of food web that begin with detritus.

Carnivore

A consumer that only eats other consumers

Herbivore

A consumer that only eats producers.

Omnivore

A consumer that eats producers and other consumers.

Detritus

Dead organic material broken down by decomposers.

Energy Pyramid

A model or pyramid that illustrates the loss of usable energy at each trophic level.

Self-Sustaining Ecosytem

An ecosystem that has a constant source of energy, autotrophs, heterotrophs, consumers, producers, and decomposers.

Energy Flow

The energy that flows through ecosystems and nutrients cycle.