Grade Population Ecology Test

Question 1

Population Ecology

Answer 1

Studying how populations live and interact with eachother.

Question 2

Population Dynamics

Answer 2

Population
Demography

Question 3

Demography

Answer 3

The statistical study of populations, allows predictions to be made about how a population will change.

Question 3

Population

Answer 3

All the individuals of a species that live together in an area

Question 4

Three key features

Answer 4

Size
Density
Dispersion

Question 5

Size

Answer 5

number of individuals in an area
Growth rate
- birth rate (natality) –> death rate (mortality)
- How many individuals are born vs. how many die
- birth rate (b) - death rate (d) = rate of natural increase (r)

Question 5

Density

Answer 5

easurement of population per unit area or unit volume.
- population density = # of individuals / unit of space

Question 6

Dispersion

Answer 6

Uniformly dispersed, clumped (Flock of bird, school of fish), random (plants)

Question 7

Density is affected by

Answer 7

1) Immigration: movement of individuals into a population.
2) emmigration: movement of individuals out of a population.
3) Density-dependent facors: biotic factors in the environment that have an increasing affect as a population size increases (disease, competition, parasites)
4) density-dependent factors: abiotic factors in the environment that effect the populations regardless of their density (temperature, weather)

Question 8

Character Displacement

Answer 8

Character displacement is a term used in evolutionary biology to describe the process by which differences are established among similar species with overlapping geographical distributions. This process involves a divergence of adaptations or other characteristics in the similar species in locations where the animals share a habitat. This divergence is spurred on by competition between the two species.

Question 9

Density Dependent

Answer 9

A density-dependent factor influences individuals in a population to a degree that varies in response to how crowded or dense the population is.

Question 9

Diffuse Competition

Answer 9

Diffuse competition is the sum-total effect of weak competitive interactions among species that are only distantly connected within their ecosystem.

Question 9

Density Independent

Answer 9

A density-independent factor influences individuals in a population in a manner that does not vary with the extent of crowding present in the population.

Question 9

Demographic

Answer 9

A demographie is a characteristic that is used to describe some aspect of a population and that can be measured for that population, such as growth rate, age structure, birth rate, and gross reproduction rate.

Question 10

Ecological Efficiency

Answer 10

Ecological efficiency is a measure of the amount of energy that is produced by one trophic level and is incorporated into the biomass of the next (higher) trophic level.

Question 10

Ecological Isolation

Answer 10

Ecological efficiency is the isolation of competing species of organisms made possible by differences in each species’ food resources, habitat use, activity period, or geographical range.

Question 11

Effective Population Size

Answer 11

The effective population size is the average size of a population (measured in the number of individuals) that can contribute genes equally to the next generation. The effective population size is in most cases less than the actual size of the population.

Question 12

Feral

Answer 12

The term feral refers to an animal that comes from domesticated stock and that has subsequently taken up life in the wild.

Question 13

Fitness

Answer 13

The degree to which a living organism is suited to a particular environment. The more specific term, genetic fitness, refers to the relative contribution the organism of a particular genotype makes to the next generation.
Those individuals exhibiting higher genetic fitness are selected for and as a result, their genetic characteristics become more prevalent within the population.

Question 14

Food Chain

Answer 14

The path that energy takes through an ecosystem, from sunlight to producers, to herbivores, to carnivores.
Individual food chains connect and branch to form food webs.

Question 15

Food Web

Answer 15

The structure within an ecological community that characterizes how organisms within the community acquire nutrition. Members of the food web are identified according to their role within it. For example, producers fix atmospheric carbon, herbivores consume producers, and carnivores consume herbivores.

Question 16

Gene Frequency

Answer 16

The term gene frequency refers to the proportion of a particular allele of a gene in the gene pool of a population.

Question 16

Gross Primary Production

Answer 16

Gross primary production (GPP) is the total energy or nutrients assimilated by an ecological unit (such as an organism, a population, or an entire community).

Question 17

Heterogeneity

Answer 17

Heterogeneity is a term that refers to the variety of either an environment or population. For example, a heterogeneous natural area is composed of numerous different habitat patches that differ from one another in various ways. Alternatively, a heterogeneous population has high levels of genetic variation.

Question 17

Intergrading

Answer 17

The term intergrading refers to the merging of characteristics of two populations where their ranges come into contact. The intergrading of morphological traits is often interpreted as evidence that the two populations are not reproductively isolated and should therefore be treated as a single species.

Question 18

K-selected

Answer 18

The term k-selected is used to describe organisms whose populations are maintained near their carrying capacity (maximum number of individuals supported by an environment).

Question 19

Mutualism

Answer 19

A type of interaction between two different species that enables both species to benefit from their interaction and in which the interaction is necessary to both. Also referred to as symbiosis.

Question 20

Niche

Answer 20

The role an organism occupies within its ecological community. A niche represents a unique way in which the organism relates to other biotic and abiotic elements of its surroundings.

Question 20

Regulatory Response

Answer 20

A regulatory response is a set of behavioral and physiological adaptations that an organism makes in response to exposure to environmental conditions. Regulatory responses are temporary and do not involve modifications in morphology or biochemistry.

Question 20

Population

Answer 20

A group of organisms of the same species that inhabit the same geographical location.

Question 21

Sink Population

Answer 21

A sink population is a breeding population that does not produce enough offspring to maintain itself in coming years without immigrants from other populations.

Question 22

Source Population

Answer 22

A source population is a breeding group that produces enough offspring to be self-sustaining and that often produces excess young that must disperse to other areas.