Populations & Communities C4.1

Question 1

Levels of ecological organization

Answer 1

individual, population, community, ecosystems, biome, biosphere

Question 2

Population

Answer 2

a group of organisms of the same species who live in the same area at the same time and able to interbreed

Question 3

Sessile organism sampling methods

Answer 3

• quadrat sampling
• line/belt transects

Question 4

Quadrat sampling

Answer 4

method used to take a measurement of an area without systematically deciding where to take it and therefore eliminates bias that may influence measurements.

Question 5

Mobile organism sampling methods

Answer 5

• pitfall traps
• pouters
• mammal traps
• nets

Question 6

Capture-Mark-Release-Recapture

Answer 6

aka the lincoln index, practical method of estimating population size of mobile animals.

Question 7

Formula for MRR technique?

Answer 7

(n1)(n2) / n3
where:
n1 = 1st capture total
n2 = 2nd capture total (marked + unmarked)
n3 = 2nd capture with only marked

Question 8

Carrying capacity

Answer 8

the maximum population that a given area can sustain. the larger a population grows, the more resources are taken from the environment.

Question 9

Density dependent factors

Answer 9

factors that depend on the population.
ex. food, water, space, avaliability of mates, etc.

Question 10

What are the 3 main groups of density dependent limiting factors?

Answer 10

competition, predation, diease

Question 11

Competition as a density dependent limiting factor?

Answer 11

high density will reduce amount of avaliable resources so compeititon increases

Question 12

Predation as a density dependent limiting factor?

Answer 12

high density will create intense predation

Question 13

Disease as a density dependent limiting factor?

Answer 13

high density means it is more likely for transmission and spread of disease.

Question 14

Density independent factors

Answer 14

factors that affect all populations in a similar way, independent of population.
ex. environmental change, injury, death from age

Question 15

What does density independent limiting factors cause?

Answer 15

population size to fluctuate due to negative feedback control, resulting in it staying stable over time

Question 16

Population growth curve

Answer 16

the growth of a population follows a sigmodial curve, an s curve in 3 stages.

Question 17

Exponential stage

Answer 17

plentiful supply of resources

Question 18

Transitional stage

Answer 18

growth rate are slower than start

Question 19

Plateau stage

Answer 19

limiting factors have a more restrictive effect

Question 20

Formula for population size using natality, mortality, emigration, and immigration

Answer 20

population size = (N+I) - (M+E)

Question 21

I + N > M+ E

Answer 21

curve up

Question 22

I + N = M + E

Answer 22

Fluctuating stable curve along carrying capacity

Question 23

I + N < M + E

Answer 23

curve down

Question 24

What causes exponential growth of population?

Answer 24

reproduction. density dependent factors of negative feedback will prevent too much

Question 25

Community

Answer 25

a group of populations living together in an area and interacting with eachother

Question 26

Intraspecific relationships

Answer 26

occuring between members of same species

Question 27

Interspecific relationships

Answer 27

occuring between members of d different species

Question 28

Intraspecific: Competition

Answer 28

between members of the same species occurs because they share same ecological niche.

Question 29

Intraspecific: Cooperation

Answer 29

all individuals benefit

Question 30

Interspecific categories

Answer 30

- herbivory - predation - competition - mutualism - paraciticism - pathogenicity

Question 31

Herbivory

Answer 31

primary consumers feeding on producers. the producer may get killed.

Question 32

Predation

Answer 32

one consumer species kills another

Question 33

Competition

Answer 33

two or more species using same resources with amount taken by one leading to reducing amount of the other

Question 34

Mutualism

Answer 34

two species living in close association with both benefiting

Question 35

Parasiticism

Answer 35

one species living on host, host harmed

Question 36

Pathogenicity

Answer 36

one species living inside another causing diease

Question 37

Examples of mutualism

Answer 37

- root nodules in fabacea - mycorrihizae in orchidaceae - zooxanthellae in hard corals

Question 38

Root nodules in Fabacea

Answer 38

- bacteria recieves protection and sugars made by the plant. - bacteria absorbs N2 and coverts to NH4 which the plants use for production of proteins preventing the plant from nitrogen deficiency.

Question 39

Mycorrihizae in Orchidaceae

Answer 39

- the fungi absorbs nitrogen, phosphorus, fixed carbon, and water from the soil and supplies them to the plant. - orchid provides fungus with carbon compounds

Question 40

Zooxanthellae in hard corals

Answer 40

- corals provide a safe and protected space for algae - the algae provides coral with glucose, amino acids, and oxygen. - coral provides CO2

Question 41

Predator-Prey relationships

Answer 41

as an example of density-dependent control of animal population. - predator kills prey does not change the population of the prey due to birth and death rates at balance.

Question 42

Top-down

Answer 42

control acts from a higher trophic level to a lower one. - increase in predator number will decrease population of prey.

Question 43

Bottom-up

Answer 43

control acts from a lower trophic level to a higher one.

Question 44

Allelopathy

Answer 44

the release of chemicals as secondary metabolites or competitive plants to grow in the same area.

Question 45

Production of antibiotics

Answer 45

many fungi produce antibiotic substances which prevent growth of oether species by intefering with cell wall components causing death.

Question 46

Endemic species

Answer 46

occur naturally in ecological niche. density dependent factors naturally control population size

Question 47

Invasive species

Answer 47

introduced by humans and not controlled due to absence of natural predators.

Question 48

Nutria

Answer 48

- destroys ecologically valuable wetland habitat by burrowing deep holes, taking away living space of endemic species. - a transmitter of disease

Question 49

Testing for interspecific competition

Answer 49

using a chi-squared test.

Question 50

Positive association

Answer 50

species found in the same habitat

Question 51

Negative association

Answer 51

species occur separately in different habitats

Question 52

No association

Answer 52

species occurs as frequently apart as together.