Communities and Ecosystems

Question 1

define a population

Answer 1

a group of interacting individuals of a particular species

Question 2

define a biological community

Answer 2

populations living close enough for potential interaction

Question 3

community ecology is concerned with…

Answer 3

factors that influence the species composition and dynamics of communities

Question 4

define interspecific interactions

Answer 4

relationships with different species in the community that greatly affect population structure and dynamics

Question 5

list 5 examples of interspecific interactions

Answer 5

1. competition
2. mutualism
3. predation
4. herbivory
5. parasites and pathogens

Question 6

competition occurs when

Answer 6

populations of two different species compete for the same limited resource

Question 7

define an ecological niche

Answer 7

the sum of an organism’s use of biotic and abiotic resources in its environment

Question 8

interspecific competition occurs when the niches of two populations…

Answer 8

overlap and both populations need a resource that is in short supply

Question 9

in general competition lowers the ________ _______ for competing populations

Answer 9

carrying capacity

Question 10

mutualism is when

Answer 10

both populations benefit

Question 11

a mutualistic relationship often evolves to be

Answer 11

obligatory symbionts

Question 12

example of mutualism

Answer 12

photosynthetic algae and reef-building corals

Question 13

describe predation

Answer 13

the predator kills and eats the prey

Question 14

adaptations in prey populations for prey avoidance includes

Answer 14

• camouflage
• mechanical defenses
• chemical defenses

Question 15

describe herbivory

Answer 15

an animal that consumes plant parts or algae

Question 16

plant defenses against herbivores include

Answer 16

• spines and thorns

- chemical toxins (sometimes used in the medical field)

Question 17

Some plants chemical defense causes….

Answer 17

abnormal development in insects that eat the plant

Question 18

Some herbivore-plant interactions illustrate…

Answer 18

coevolutions

Question 19

define coevolution

Answer 19

a series of reciprocal evolutionary adaptations in two species

Question 20

examples of coevolution include..

Answer 20

• monophagy (butterflies that only eat a specific leaf)

- chemical incorporations (toxic butterflies or plants with egg spots)

Question 21

describe parasitism

Answer 21

host plants/animals are victimized by parasites or pathogens

Question 22

non-native pathogens can have…

give an example

Answer 22

rapid and dramatic impacts

-American chestnut being devastated by the chestnut blight protist

Question 23

define trophic structure

Answer 23

a pattern of feeding relationships consisting of different levels

Question 24

a food chain is known as

Answer 24

the sequence of food transfer up the trophic levels

Question 25

producers are

Answer 25

autotrophs that support all other trophic levels

Question 26

consumers are...

Answer 26

heterotrophs

Question 27

herbivores are..

Answer 27

primary consumers

Question 28

secondary consumers typically eat

Answer 28

herbivores

Question 29

tertiary consumers typically eat

Answer 29

secondary consumers

Question 30

quaternary consumers typically eat

Answer 30

tertiary consumers

Question 31

define detritus..

Answer 31

the dead material produced at all the trophic levels

Question 32

detritivores derive their energy from...

Answer 32

detritus

Question 33

decomposers are mainly..

Answer 33

prokaryotes and fungi

Question 34

decomposers have ______ _______.

Answer 34

secretion enzymes

Question 35

define decomposition

Answer 35

the conversion of organic molecules into inorganic molecules through the digestion of decomposers

Question 36

define a food web

Answer 36

a network of interconnecting food chains

Question 37

what is a more realistic view of the trophic level of a community?

Answer 37

a food web

Question 38

species diversity is defined by...

Answer 38

- species richness | - relative abundance

Question 39

species richness is the

Answer 39

of different species in a community

Question 40

relative abundance is the...

Answer 40

proportional representation of a species in a community

Question 41

low species diversity is characteristic to most

Answer 41

modern agricultural ecosystems

Question 42

high diversity areas have lots of species at

Answer 42

intermediate abundance

Question 43

what is a way to measure the species diversity

Answer 43

- absolute richness | - Shannon entropy index

Question 44

species diversity can often drive other

Answer 44

ecological processes/ measures

Question 45

define the edge effect

Answer 45

the greatest biological diversity occurs where two ecosystems meet

Question 46

describe keystone species

Answer 46

one whose impact on its community is larger than its biomass; occupies a niche that holds the rest of its community in place

Question 47

examples of keystone species

Answer 47

- sea otters and kelp - urchins and orcas - gopher tortoises in longleaf pine forests

Question 48

disturbances are events that..

Answer 48

damage biological communities and include storms, fires, floods, drought, human activity

Question 49

small-scale disturbances often have a...

Answer 49

positive effect

Question 50

ecological succession is a...

Answer 50

transition in species composition of a community

Question 51

primary succession is the...

Answer 51

gradual colonization of barren rocks

Question 52

secondary succession occurs after...

Answer 52

a disturbance has destroyed a community but left the soil intact

Question 53

characteristics of invasive species..

Answer 53

1. have been introduced to non-native habitats by humans 2. established at the expense of native communities 3. can spread from introduction site

Question 54

invasive species can become

Answer 54

naturalist- self-sustaining

Question 55

examples of invasive species

Answer 55

- fire ants | - burmese pythons in South Florida

Question 56

ecosystem ecology emphasized

Answer 56

energy flow and chemical cycling

Question 57

an ecosystem consists of

Answer 57

- all organisms in a community | - organisms' interaction with abiotic environment

Question 58

energy flow moves...

Answer 58

through the components of an ecosystem

Question 59

chemical cycling is the...

Answer 59

transfer of materials within the ecosystem

Question 60

define primary production

Answer 60

the conversion of solar energy to chemical energy by photosynthesis

Question 61

gross primary production is the

Answer 61

total amount of primary production during a given time period

Question 62

define net primary production

Answer 62

the amount of new organic material added to an organism in a given period

Question 63

primary production varies in

Answer 63

different environments

Question 64

only about ___ of available sunlight is converted to organic compounds by plants

Answer 64

3%

Question 65

only about ___ of the energy stored at each trophic level is available to next level

Answer 65

10%

Question 66

when humans eat grain or fruit we are...

Answer 66

primary consumers

Question 67

when humans eat beef we are

Answer 67

secondary consumer

Question 68

when humans eat fish, trout, salmon we are

Answer 68

tertiary/ quaternary consumers

Question 69

chemicals are cycled between...

Answer 69

organic matter and abiotic reservoirs

Question 70

ecosystem are supplied with a constant influx of energy from

Answer 70

the sun and Earth's interior

Question 71

There are no extraterrestrial sources of chemical elements except for

Answer 71

meteorites

Question 72

life depends on...

Answer 72

the recycling of chemicals

Question 73

biogeochemical cycles include what 3 things

Answer 73

1. biotic components 2. abiotic components 3. abiotic reservoirs

Question 74

biogeochemical cycles can be

Answer 74

local or global

Question 75

list 3 examples of biogeochemical cycles

Answer 75

- carbon - phosphorus - nitrogen

Question 76

carbon is the..

Answer 76

major ingredient of all organic molecules

Question 77

where is the reservoir for carbon?

Answer 77

in the atmosphere

Question 78

carbon cycles...

Answer 78

globally

Question 79

carbon resides in plant and animal

Answer 79

biomass, fossil fuels, soils, sedimentary rock, and as dissolved carbon

Question 80

where does carbon enter the ecosystem?

Answer 80

through wood and fossil fuels

Question 81

the phosphorus cycle depends on...

Answer 81

the weathering of rock

Question 82

Organisms usually require phosphorus in the form of...

Answer 82

phosphate ion PO4 ^3-

Question 83

phosphorus is an ingredient of

Answer 83

- nucleic acids, phospholipids, ATP, | - as mineral component of bones and teeth

Question 84

Phosphorus DOES NOT have a ______ ______ compared to carbon cycle.

Answer 84

atmospheric component

Question 85

phosphates are transferred from terrestrial to aquatic ecosystems more rapidly than...

Answer 85

they are replaced

Question 86

why is the phosphorus cycle considered "local"?

Answer 86

there's no atmospheric component

Question 87

Nitrogen is an ingredient to

Answer 87

proteins and nucleic acids

Question 88

nitrogen is essential to the

Answer 88

structure and functioning of all organisms

Question 89

nitrogen can be described as what ______ and _______ as a plant nutrient.

Answer 89

crucial limiting

Question 90

What are nitrogen's 2 abiotic reservoirs?

Answer 90

1. the atmosphere (80%) | 2. soil

Question 91

What are the 3 types of bacteria?

Answer 91

1. ammonifying bacteria 2. nitrogen fixing bacteria 3. nitrifying bacteria

Question 92

what charge do ammonium and nitrate have?

Answer 92

a positive one

Question 93

nitrogen fixation converts...

Answer 93

N2 to compounds of nitrogen that can be used by plants

Question 94

describe how denitrifying bacteria works

Answer 94

under low oxygen conditions soil bacteria strip O from NO3- releasing N2

Question 95

in aquatic ecosystem primary production is limited by

Answer 95

-low nutrient levels of phosphorus and nitrogen

Question 96

define eutrophication

Answer 96

excessive richness of nutrients in a body of water

Question 97

eutrophication results in

Answer 97

- decreased species diversity | - oxygen depletion in body of water

Question 98

characteristics of eutrophication

Answer 98

- cyanobacteria and dinoflagellates replace native aquatic plants - outcompete and crash natural ecosystems - consume oxygen - produce toxins

Question 99

eutrophication causes...

Answer 99

oceanic dead zones

Question 100

Human rely on natural ecosystems to

Answer 100

- supply fresh water and foods - recycle nutrients - decompose wastes - regulate climate/ air quality

Question 101

examples of ecosystem services include

Answer 101

- wetlands | - natural vegetation

Question 102

wetlands purpose...

Answer 102

- buffer against tidal waves - reduce the impact of flooding rivers - filter pollutants

Question 103

natural vegetation helps to

Answer 103

- retain fertile soil | - prevent landslides and mudslides