Unit 4: Populations & Community Dynamics (Day 11)

Front 1

Define gene pool.

Back 1

the various alleles of all the genes in all the members of a population

Front 2

Define genetic equilibrium.

Back 2

allele frequency remains stable which results in no evolution occurring

Front 3

Name the five conditions that must be met to maintain genetic equilibrium.

Back 3

1. Large population - no genetic drift

2. No mutations

3. No migration

4. No natural selection

5. Random mating

Front 4

Define natural selection.

Back 4

organisms that are better adapted to their environment tend to survive and produce more offspring

Front 5

Define genetic drift

Back 5

changes to the allele frequency as a result of chance

Front 6

Define gene flow

Back 6

the movement of alleles from one population to another

Front 7

Define the bottleneck effect

Back 7

big to small population = not very much variability in alleles and a change in the frequency

Front 8

Define the founder effect

Back 8

when individuals find a new colony, only a fraction of the original gene pool is represented

Front 9

Define non random mating.

Back 9

pairing up not by chance but according to genotype and phenotype

Front 10

What do mutations do to the gene pool?

Back 10

changes the allele frequency with new alleles

Front 11

Define carrying capacity

Back 11

the maximum population that can be maintained by a given supply of resources

Front 12

Define biotic potential

Back 12

the ability of a population to increase under ideal environmental conditons

Front 13

Define environmental resistance

Back 13

resources that LIMIT a population from reaching biotic potential

Front 14

As the number of individuals increase, what happens to the environmental resistance?

Back 14

it increases

Front 15

What is the formula for calculating the growth rate?

Back 15

change in individuals / change in time

Front 16

What is the formula for calculating the per capita growth rate?

Back 16

change in population size / initial population size

Front 17

What is the formula to calulate population density?

Back 17

Total number of individuals / area or volume

Front 18

Explain exponential growth. (6)

Back 18

1. J-shaped curve.

2. The population size increases by a fixed rate per a fixed unit of time

3. unlimited resources

4. only limit on growth is biotic potential

5 natality is always higher than morality

6. 4 phases (log, growth, stationary, death)

Front 19

Explain Logistic growth. (2)

Back 19

1. S - shaped curve

2. 3 phases (log, growth & stationary)

Front 20

Define open population.

Back 20

a population in which change in number and density is determined by natality, mortality, emmigration and immigration

Front 21

Define closed population.

Back 21

a population in which change in number and density is determined only by natality and mortality

Front 22

Draw a chart concerning the difference between K selected and R selected species.

Back 22

sheet is on google docs.

Front 23

Define density-dependant factors

Back 23

Factors that limit population growth only at a specific density (number)

Front 24

Define density independant factors

Back 24

facors that has the smae influence on a population at any population density

Front 25

Name 3 Density dependant factors

Back 25

food, space, competition, predation, DISEASE, resources

Front 26

Name 3 Density independant factors

Back 26

pesticide use, weather, chemicals, floods, fires, herbicides

Front 27

Define intraspecific competition

Back 27

competition between the same species

Front 28

Define interspecific competition

Back 28

competition between different species

Front 29

Define commensalism (who benefits or doesn't and give an example)

Back 29

one organism benefits while the other is neutral. ex. barnacles on a whale

Front 30

Define mutualism (who benefits or doesn't and give an example)

Back 30

Both organisms benefit from the relationship. ex. bees and flowers D

Front 31

Define parasitism (who benefits or doesn't and give an example)

Back 31

the parasite benefits while the host is ususually harmed or even killed. ex. tape worms

Front 32

Define succesion

Back 32

the slow, progessive replacement of one community by another

Front 33

Define climax community.

Back 33

the final, relatively stable community reached dring successional stages

Front 34

Define primary succesion and give its key event

Back 34

occupaton by plant life of an area not previously covered by vegetation. key event = soil production

Front 35

Define pioneer species. give an example

Back 35

first species to appear during succesion. ex. moss

Front 36

What is secondary sucession caused by? give an example

Back 36

a disturbance to habitat. ex fire