Biology 1010 Exam 5 Review

Ch. 37, 38, 39, 40 + cumulative

Ecology

The study of the relationships that organisms have with each other and with the environment

Population

A group of interbreeding organisms of one species occupying a location at the same time

Community

Includes all of the populations, representing multiple species, that interact in a given area

Ecosystem

A community plus its nonliving environment, including air, water, minerals, and fire

Habitat

The physical location where the members of a population normally live

Population Density

The number of individuals of a species per unit area or unit volume of habitat

Population Distribution

Patterns describe how individuals are scattered through the habitat space

• Random

• Uniform

• Clumped

Population Dynamics

The study of the factors that influence changes in a population’s size

Immigration

The movement of individuals into a population

Emigration

Occurs when individuals leave

Birth Rate

The number of new individuals produced per individual in a defined time period

Age Structure

Distribution of age classes in a population, helps determine its birth rate

Death Rate

The number of deaths per unit time, scaled by the population size

Life Table

A chart that shows the proportion of surviving individuals at each age

Survivorship Curve

A graph of the proportion of surviving individuals at each age

Per Capita Rate of Increase (R)

The difference between the birth rate and the death rate

Exponential Growth

The number of new individuals is proportional to the population’s size

J-Shaped Curve

Emerges when exponential growth is plotted over time

Environmental Resistance

The combination of external factors that keep a population from reaching its maximum growth rate.

Carrying Capacity

The maximum number of individuals that the ecosystem can support indefinitely

Logistic Growth

The early growth of a population may be exponential, but growth slows and eventually ceases as the population’s size approaches the habitat’s carrying capacity

S-Shaped Curve

Depicts the leveling off a population in response to environmental resistance

Density-Dependent Factors

Conditions whose growth-limiting effects increase as a population grows

Biotic

Living, density-dependent limits are mostly a result from interactions with living organisms

Density-Independent Factors

Exert effects that are unrelated to population density

Abiotic

Nonliving, most density-independent limits are abiotic

Life History

Includes all events of an organism’s life from conception through death

Opportunistic Life History

Individuals tend to be short-lived, reproduce at an early age, and have many offspring that receive little to no care

Equilibrium Life History

Individuals tend to be long-lived, to be late maturing, and to produce a small number of offspring that receive extended parental care

Demographic Transition

Birth rates and death rates shift from high to low

Ecological Footprint

Measures the amount of land area needed to support a person’s or a country’s overall lifestyle

Niche

All resources a species uses for survival, growth, and reproduction

Competition

Occurs when two or more organisms vie for the same limited resource, such as shelter, nutrients, water, light, or food

Competitive Exclusion Principal

Two species coexist indefinitely in the same niche

Resource Partitioning

Multiple species use the same resource in a slightly different way or at a different time

Symbiosis

Two species share a close relationship in which one typically lives in or on the other

Mutualism

A symbiosis relationship that improves the fitness of both partners

Commensalism

A type of symbiosis in which one species benefits but the other is not significantly affected

Parasitism

One species acquires resources at the expense of a living host

Herbivore

An animal that consumes plants

Carnivore

Eats meat

Predator

A carnivore that kills and eats other animals called prey