Unit 3

Question 1

Interspecific competition

Answer 1

Competition between different species

Question 2

Intraspecific competition

Answer 2

Competition a among members of the same species

Question 3

Competitive exclusion principle

Answer 3

• If in two species are in direct competition with each other, one must win outright, adapt by resource partitioning or character displacement, migrate, or die out
• Also called Gause’s law

Question 4

Resource partitioning

Answer 4

The evolution of specialized traits by different species to reduce competition between species for similar scarce resources

Question 5

Predation

Answer 5

A member of one species (predator) feeds on all or part of another species (prey)

Question 6

Coevolution

Answer 6

The natural selection process in which changes in the gene pool of one species leads to changes in the gene pool of another species

Question 7

Parasitism

Answer 7

A species interaction in which one species (the parasite) lives in or on and preys on another species (the host)

Question 8

Mutualism

Answer 8

A species interaction in which both species benefit

Question 9

Commensalism

Answer 9

A species interaction in which one species benefits and the other is unaffected

Question 10

Symbiosis

Answer 10

A mutually beneficial relationship between two species

Question 11

Population

Answer 11

A group of interbreeding individuals of the same species

Question 12

Limiting factors

Answer 12

• A factor that limits the growth of a population
• Also called environmental resistence

Question 13

Carrying capacity

Answer 13

The maximum number of individuals that an environment can sustain for an indefinite time

Question 14

R-selected species

Answer 14

• A species with a high capacity for growth
• Gives birth to many offspring which mostly die in early early life
• Also called r-strategists

Question 15

K-selected species

Answer 15

• A species with a low capacity for population growth
• Gives birth to few offspring and care for them, many reach adulthood
• Also called k-strategists

Question 16

Survivorship curve

Answer 16

• Illustrates different life expectancies of species by showing percentages of members of different ages
• Three types: late loss (k-strategists), early loss (r-strategists), constant loss (constant death rate at all ages)

Question 17

Cultural carrying capacity

Answer 17

The maximum number of people who could live in a reasonable freedom and comfort indefinitely, without decreasing the ability of the earth to sustain future generations

Question 18

Crude birth rate

Answer 18

The number of live births per 1000 people in a population in a given year

Question 19

Crude death rate

Answer 19

The number of death per 1000 people in a population in a given year

Question 20

Total Fertility Rate (TFR)

Answer 20

The average number of children born to women of childbearing age in a population

Question 21

Infant mortality rate

Answer 21

The number of babies out of every 1000 born who die before their first birthday

Question 22

Migration

Answer 22

The movement of people into (immigration) and out of (emigration) specific geographic areas

Question 23

Age structure

Answer 23

The distribution of individuals among various age groups in a population

Question 24

Demographic transition

Answer 24

• The theory that as a country industrializes and population grows, the crude birth and crude death rate decrease, slowing population growth
• Takes place in four stages: preindustrial, transitional, industrial, postindustrial

Question 25

Habitat

Answer 25

A general physical place of residence in an environment

Question 26

Niche

Answer 26

The functional role of an organism in a community

Question 27

Ecological equivilants

Answer 27

• Two species from different taxonomic categories that have comparable niches and habitats in different places • The outcome of convergent evolution • The Australian Tasmanian wolf and the Ethiopian lion are ecological equivalents because they are both running carnivorous mammals (the same niche)

Question 28

Size of an population

Answer 28

• Increases with births and immigration • Decreases with deaths and emigration

Question 29

Estimation methods for population size

Answer 29

• Extrapolation based in a few points • Mark, release, recapture (used for hard to count, mobile organisms) • Mark, release, recapture uses the Lincoln-Peterson index

Question 30

Population density

Answer 30

Low density populations are territorial or widely dispersed species (may be apex predators) and high density populations are social species or overpopulated

Question 31

Population dispersion

Answer 31

Three kinds: uniform, clumped, and random dispersion

Question 32

Age structure

Answer 32

The distribution of individuals among various age groups in a population

Question 33

Factors that effect population growth

Answer 33

• Age at which reproduction begins • Number of offspring per reproduction • How often reproduction occurs (semelparous or iteroparous) • Reproductive timespan • Changes of survival until age of reproduction • Immigration and emigration

Question 34

Semelparous

Answer 34

Reproduction occurs only once in a lifetime

Question 35

Iteroparous

Answer 35

Reproduction occurs 2+ times in a lifetime

Question 36

Biotic potential

Answer 36

The maximum number of organisms that can live in an environment

Question 37

Density independent factors

Answer 37

* Not related to concentration of organisms * Organisms have no control over them * Will affect over or under populated populations * Inclement weather, man-made disasters, natural disasters

Question 38

Density dependent factors

Answer 38

* Effects depend on abundance of the population * These are evolutionary in nature * Resources, predators, competition, invasive species

Question 39

Predator strategies

Answer 39

Speed, agility, venom and weapons, trapping and attracting

Question 40

Prey countermeasures

Answer 40

* Constant vigilance, bluff * Physical defenses (porcupine spines, cactus spines) * Chemical deterrents (bombardier beetles spray acid) * Speed and agility * Camouflage or cryptic coloration (leaf bugs, orchid mantis) * Aposematic (warning) coloration (bright reds, yellows, etc.) * Startle coloration (butterflies with eye patterns)

Question 41

Batesian mimicry

Answer 41

Once species is poisonous and the other is harmless (monarch and viceroy)

Question 42

Mullerian mimicry

Answer 42

Both species are dangerous and enforce each others' threat to predators (most wasps and yellow-black striped insects)

Question 43

Invasive species

Answer 43

* Any species that is not native to a given area * Compete with native animals over the same niche * May not have natural predators * Zebra mussels, Anacondas