Ecology Flashcards Preview

SAT II BIOLOGY > Ecology > Flashcards

Flashcards in Ecology Deck (52):
1

What is population defined by?

Size, density, and dispersion

2

Size

Total number of individuals in a population: births, deaths, immigration, emigration

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Density

Number of individuals per unit area or volume

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Dispersion

Pattern of spacing of individuals: clumped, uniform random spacing

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Biotic potential

The maximum rate at which a population could increase under ideal conditions

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What factors influence a population's biotic potential?

-Age at which reproduction begins
-Life span capable of reproducing
-Number of reproductive periods in lifetime
-Number of offspring capable at 1 time

7

Carrying capacity(K)

The maximum that the environment can support

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r-strategists

-Reproduce rapidly when uncrowded and resources are vast
-Many, small young
-Little parenting
-Rapid maturation
-reproduce once
-Insects

9

K-strategists

-Maximize population size near the carrying capcity
-Few, large young
-Intensive parenting
-slow maturation
-Reproduce many times
-Mammals

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Limiting factors

-Limit population growth
-Density-dependent factors and Density-independent factors

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Density-dependent factors

-Increase directly as the population density increases
-Competition for food, buildup of wastes, predation, disease

12

Density-independent factors

-Occurence is unrelated to the population density
-Natural disasters

13

Population interactions

Competition, predation, parasitism, mutualism, commensalism

14

G. F. Gause

Competitive exclusion principle

15

Competitive exclusion principle

-2 species can't coexist in a community if they share a niche, if they compete for the same resources

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What happens if 2 species share the same niche in a community?

-extinction
-Evolve through natural selection to exploit different resources - resource partitioning
-character displacement(divergence in adaption)

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Character displacement

adaptive radiation

18

Resource partitioning

Evolve through natural selection to exploit different resources

19

Passive defenses against predators

1. Aposematic coloration
2. Batesian mimicry
3. Mullerian mimicry

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Aposematic coloration

Bright coloration of poisonous animals is a warning that predators should avoid them

21

Batesian mimicry

-Copycat coloration
-Harmless animal mimics the coloration of a poisonous animal

22

Mullerian mimicry

2 or more poisonous species resemble eachother and predators learn to avoid any prey with that appearance

23

Detritivores

-Animals that feed on organisms that have died and decomposed into organic matter(detritus)

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detritus

decomposed organic matter

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Productivity

The rate at which organic matter is created by producers

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Gross primary productivity

The amount of energy converted to chemical energy by photosynthesis per unit time in an ecosystem

27

NEt primary productivity

The gross primary productivity minus the energy used by the producers for respiration

28

Biological magnification

Organisms occupying higher trophic levels have greater concentration of accumulated toxins stored in their bodies

29

Primary ecological succession

Rebuilding of ecosystem in a lifeless area where soil has been removed

30

What is the essential and dominant characteristic of primary ecological succesion?

soil building

31

Eutrophication

-Disruption of freshwater ecosystems
-Runoff from sewage and manure increase nutrients in lakes and cause excessive growth
-Organic material accumulates on the bottom, reduces the depth
-Detritivores use up oxygen as they decompose organic matter

32

Acid Rain

-Caused by pollutants in the air from combustion of fossil fuels
-Nitrogen and sulfur pollutants cause pH of rain be less than 5.6

33

Greenhouse effect

-global warming
-Burning of fossil fuels caused the concentrations of CO2 in the air to increase
-CO2 and water vapor absorb infrared radiation reflecting off Earth, and temp rise

34

Chlorofluorocarbons

Chemicals used for refrigerants and aerosol cans

35

Depletion of Ozone Layer

-Accumulation of chlorofluorocarbons formed a hold in the ozone layer
-more ultraviolet light reach Earth, increase of skin cancer

36

Decomposer

-absorb most breakdown products and recycle nutrients back to the soil to nourish plants

37

Diatoms

Photosynthetic protists in the ocean

38

Phytoplankton

algae and photosynthetic bacteria in aquatic environments

39

Primary ecological succession

Rebuilding of ecosystem in a lifeless area where soil has been removed

40

What is the essential and dominant characteristic of primary ecological succesion?

soil building

41

Eutrophication

-Disruption of freshwater ecosystems
-Runoff from sewage and manure increase nutrients in lakes and cause excessive growth
-Organic material accumulates on the bottom, reduces the depth
-Detritivores use up oxygen as they decompose organic matter

42

Acid Rain

-Caused by pollutants in the air from combustion of fossil fuels
-Nitrogen and sulfur pollutants cause pH of rain be less than 5.6

43

Acid Rain

-Caused by pollutants in the air from combustion of fossil fuels
-Nitrogen and sulfur pollutants cause pH of rain be less than 5.6

44

Greenhouse effect

-global warming
-Burning of fossil fuels caused the concentrations of CO2 in the air to increase
-CO2 and water vapor absorb infrared radiation reflecting off Earth, and temp rise

45

Depletion of Ozone Layer

-Accumulation of chlorofluorocarbons formed a hold in the ozone layer
-more ultraviolet light reach Earth, increase of skin cancer

46

Decomposer

-absorb most breakdown products and recycle nutrients back to the soil to nourish plants

47

Diatoms

Photosynthetic protists in the ocean

48

Phytoplankton

algae and photosynthetic bacteria in aquatic eenvironments

49

Nitrogen-fixing bacteria

Live in the nodules in the roots of legumes and convert free nitrogen into ammonia

50

Nitrifying bacteria

Convert ammonia into nitrites and then into nitrates

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Denitrifying bacteria

convert nitrates into free nitrogen

52

Decomposers

Bacteria that break down dead organic matter into ammonia