Discovery Ed Bio Flashcards

What do population ecologists study?

They study all of the factors that impact a population over time.

Abotic factors include:

temperature, precipitation, sunlight

Biotic factors include:

prey, parasites, predators

Can populations increase or decrease due to natural causes?

Yes.

Can populations grow indefinitely?

No.

Ecosystem

All living and non-living components in an area

Community

collection of populations that interact together

Species

Organisms that share the same characteristics and features

Population

the number of individuals of the same species in an area

What is the equation used to calculate the rate of a population's growth?

G = rN (r = rate of increase, N = current size of population)

population density

the number of individuals per unit area

How does clumped distribution occur?

Where resources are unevenly dispersed or the individuals have positive interactions

How does uniform distribution occur?

When individuals have negative interactions and do not like to stay together

How does random distribution occur?

When there are neutral interactions between individuals

Which distribution is the most uncommon?

Random distribution

Population demographics

The study of a population's structure, health, and interactions

Density dependent factors

Factors in an ecosystem that correlate with the population density, generally biotic

Examples of density dependent factors include:

disease, competition, predation

Density independent factors

Factors in an ecosystem that do not correlate with the population density, generally abiotic

Some density independent factors include:

weather, pollution, non infectious diseases

Exponential growth is _____.

constant

What conditions allow for exponential growth?

ideal conditions and no limitations

r-selected rely on _____ growth

exponential

r-selected organisms tend to be:

small, grow quickly, have a lot of offspring, and no parental care

Logistical growth

When a population grows exponentially until they are limited by limitations

K-selected organisms rely on ______ growth

Logistical

K-selected organisms tend to:

be larger, grow slowly, produce fewer offspring, and provide parental care

Carrying capacity

the maximum population size that can be maintained in a particular environment

An age pyramid shows the ______

age distribution of a population

Survivorship curve is a ______

graph that shows rates of survival for various ages

Type 1 survivorship curve

long life spans, the survival rate begins to decline towards older ages

Type 2 survivorship curve

consistant death rate, looks like a straight line (they are always faced with the threat of mortality)

Type 3 survivorship curve

mortality rates are higher for younger ages than older ages. they tend to produce more offspring since less survive

Malthusian theory

the rapid increase of human population is stabilized by famine, war, or disease

Lotka-Volterra competition model

When two species compete for the same food source, their populations are affected

Population growth equation

(birth rate-death rate)/population size