Unit 4 - Population Dynamics

Question 1

Hardy-Weinberg Principle

Answer 1

1) Large Population
2) Random Mating
3) No Net Mutations
4) No Migration
5) No Natural Selection

Question 2

Population Distribution Patterns

Answer 2

1) UNIFORM: Area between individuals is equal, space for each individual is maximized. (Territorial species, made-made population).

2) RANDOM: Position of an individual is independent of others. Least common.

3) CLUMPED: Each individual lives close to neighbors, but clumped are spaced according to resources. Most common.

Question 3

Open Population

Answer 3

Affected by birth, death, immigration, emigration.

Question 4

Closed Population

Answer 4

Affected by birth and death only.

Question 5

Changing Allele Frequency

Answer 5

1) Mutations
2) Gene Flow
3) Non-Random Mating
4) Genetic Drift
5) Natural Selection

Question 6

Mutations

Answer 6

INHERITABLE: occurs in gametes, allele to be passed on. Can provide SELECTIVE ADVANTAGE to some.

Question 7

Gene Flow

Answer 7

Movement of alleles between population due to MIIGRATION.

Question 8

Non-Random Mating

Answer 8

Choosing mates based on physical/behavioral traits.

Question 9

Genetic Drift

Answer 9

Chance event that changes allele frequencies. Usually affects small populations more than large.
–>FOUNDER EFFECT: a few individuals leave original population and form a new one.
–>BOTTLENECK EFFECT: a population size rapidly decreased, leaving a few individuals to repopulate.

Question 10

Natural Selection

Answer 10

If some alleles have a selective advantage, the frequency of those alleles will increase.

Question 11

Biotic Potential (r)

Answer 11

Highest possible cgr for a population with unlimited resources and ideal condition.

Determined By:
1) # of offspring per reproductive cycle.
2) # of offspring surviving to reproductive age.
3) Age of reproductive maturity.
4) Life span of individuals and the # of times they reproduce in their lifetime.

Question 12

Carrying Capacity (K)

Answer 12

Maximum population an environment can sustain.

Question 13

Exponential Growth

Answer 13

Population growing at biotic potential. J-curve. Closed population.

Question 14

Logistic Growth

Answer 14

As a population grows, growth rate slows as it approaches K. S-curve. Open population.

Question 15

Density-Dependent (Biotic)

Answer 15

Arise from population density.
–> Limited food/resources, competition, predation, paasition.
–>Affects big, dense population.

Question 16

Density-Independent (Abiotic)

Answer 16

Affect population size regardless of size/ density.
–> Temperature, precipitation, natural selection.

Question 17

All Limiting Factors

Answer 17

Environmental resistance.
–> Environmental resistance determines K, prevents populations from growing at biotic potential.

Question 18

R-Selected

Answer 18

Takes advantage of favorable conditions. Reproduces close to biotic potential. Short lifespan. Reproductive at early age, man offspring per reproductive cycle. Little to no potential care after birth.

Question 19

K-Selected

Answer 19

Spends more energy/resources on helping every offspring survive. Big reproductive cycle, few offspring per cycle. Long life-span, takes longer to reach sexual maturity. Potential care after birth.

Question 20

Sustaintability

Answer 20

Meeting needs whiles keeping enough resources for the future.

Question 21

Age Pyramids

Answer 21

Triangle: Population growing.

Rectangle: Stable population.

Inverted Triangle: Population declining.

Question 22

Intraspecific Competition

Answer 22

Within the same species. Density dependent. Organisms avoid competition by dispersing offspring.

Question 23

Interspecific Competition

Answer 23

Within different species. The more two species niches overlap, the more competition. Density dependent.

Invasive: Can outcompete and wipe out native species.

Question 24

Defense Against Predators

Answer 24

Protective Coloration: bright colors signal danger to other species.
–> Camouflaged
–> BASTESIAN MIMICRY: An organism resembles another with defense mechanism, despite not having that mechanism.
–> MULLERIAN MIMICRY: Two organisms resemble each other, both have defense mechanism.

Question 25

Symbiotic Relationships

Answer 25

(+/+): Both Benefit
(+/0): One benefits the other is unaffected
(+/-): One benefits, the other is harmed.

Question 26

Primary Succession

Answer 26

Building an ecosystem from scratch, in an area with no soil.
PIONEER SPECIES: grow on rock, break down to form soil and eventually forms climax community.

Question 27

Secondary Succession

Answer 27

Repopulating an area after a disturbance. Can reach climax community faster than primary.