AP Biology - Chapters 19 + 20: Speciation and Ecology (Vocab)

Species

Individuals capable of interbreeding 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

Pre-zygotic isolating mechanisms

Prevents fertilization of eggs

Spacial Mechanism

Selects different places to live and or reproduce

Behavioral Mechanism

Differ in mating behaviours such as visual cues or vocalization

Tempooral Mechanism

Reproduce during different times so mating periods don't overlap

Mechanical Mechanism

Reproductive organs incompatible because of size or shape

Gametic Mechanism

Sperm or egg are incompatible

Post zygotic isolating mechanism

Zygote forms but embryo doesn't survive or it survives and is sterile

Extinction

Death of all members of a species

Mass Extinction

Episode during which large members of a species become extinct

Ecology

Study of the interactions among organisms and their physical environments

Population

All members of one species inhabiting an area

Community

All different species interacting in one area

Ecosystem

All the living and nonliving components of a habitat

Biome

One of world's major ecosystems

Biosphere

Part of Earth occupied by living organisms

Biotic

Pertaining to life

Abiotic

Pertaining to non-living

Producers

Organisms that change energy into food

Consumers

Organisms that eat producers or other consumers

Decomposers

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

Symbiotic Relationship

Ecological interactions that involve 2 different species that live together in direct contact

Commensalism

Symbiotic relationship in which 1 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

Symbiont

Parasite

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

Resovoir

Source unavailable to producers

Exchange Pool

Source from which organisms take chemicals

Biotic Community

Chemicals move through community along food chains

Gaseous Cycle

Chemical element is drawn from and returns to the atmosphere

Sedimentary Cycle

Chemical element is drawing from soil by plant roots, eaten by consumers, returned to soil by decomposers

Condensation

Process of a gas changing to a liquid

Transpiration

Process of evaporation of water from plants

Nitrogen Fixation

Conversion of nitrogen gas (N2) to ammonium ions (NH4)

Nitrification

Production of nitrate which plants can use

Denitrification

Conversion of nitrate back to nitrogen gas by denitrifying bacteria

Eutrophication

Over-enrichment of water caused by humans that leads to excessive algal and bacterial growth and oxygen depletion

Growth Rate

Per capita rate of increase

Biotic Potential

Highest per capita rate of increase for a population

Lag Phase

Growth is small because the population is small

Experimental growth phase

Growth is accelerating and the population is exhibiting its biotic potential

Deceleration Phase

The rate of population growth slows down

Stable Equilibrium Phase

Little if any growth takes place because births and deaths are about equal

Carrying Capacity

The number of individuals of a species that a particular environment can support

Limiting Factors

Factors that limit population growth

Cohort

Group of individuals born at the same time

Type 1 Survivorship Curve

Most individuals survive till old age

Type 2 Survivorship Curve

Decreases consistently over time

Type 3 Survivorship Curve

Most individuals die early

Doubling Time

Length of time it takes for a population size to double

Density-independent factors

Abiotic factors

R-Selection

Selection for life history traits that are sensitive to density-independent factors

R-Selected Species

Species in which population is controlled by abiotic factors

Density-dependent factors

Biotic factors

K-Selection

Selection for life history traits that are sensitive to density-dependent factors

K-Selected Species

Species in which population is controlled by biotic factors

Competition

Interaction between 2 organisms in which both require the same limited resource