chapter 17: Communities and Ecosystems

Question 1

ecosystems

Answer 1

a community of biological organisms plus the abiotic components with which the organisms interact

Question 2

biotic environment

Answer 2

living organisms within an area (aka community)

Question 3

abiotic environment

Answer 3

chemical resources (soil, water, air) and physical conditions (temp., salinity, moisture, humidity and energy sources) within an area (aka habitat)

Question 4

biomes

Answer 4

cover huge geographic areas of water/land
- determined by temp. rainfall and consistency of both
- tropical rain forests, savannas, chaparral, temperate grasslands, desert, tundra, coniferous forest, temperate deciduous forest, polar ice

Question 5

aquatic biomes

Answer 5

estuaries: tidal water passage, linked to sea, high productivity
lakes and ponds, rivers and streams, intertidal zones, coral reefs, wetlands, open oceans

Question 6

distribution of solar energy

Answer 6

due to curvation of the earth, sunlight directly hits equator but poles at steep angle

Question 7

warming the air and rain

Answer 7

hot air rises, as it rises it cools, cool air holds less moisture, clouds form and moisture falls as rain

Question 8

formation of deserts

Answer 8

1. warm air rises away from Earth’s surface and becomes cooler
2. cool air falls toward earth surface and becomes warmer
3. warm air holds more moisture which means very little rainfall

Question 9

topography

Answer 9

reflex physical features of land (including manmade)

Question 10

rain shadows

Answer 10

create deserts; area in lee of a mtn. where there is no/reduced rainfall because air passes over mtn. falls becoming warming holding moisture

Question 11

ocean circulation patterns

Answer 11

circular patterns of flowing water in oceans due to a combination of forces
wind, earths rotation, gravitational pull of moon, temperature, salt concentration

Question 12

el nino

Answer 12

warm water doesn’t move away and cold water doesn’t up well
- flooding, droughts, famine, variety of other extreme weather disruptions

Question 13

la nina

Answer 13

ocean surface temperature lower than usual
- weather affects opposite of el nino

Question 14

trophic levels

Answer 14

a step in the flow of energy through an ecosystem

Question 15

producers

Answer 15

primary productivity; plants convert light energy from the sun into food through photosynthesis

Question 16

primary consumers

Answer 16

herbivores; animals that eat plant

Question 17

secondary consumers

Answer 17

carnivores; animals that eat herbivores

Question 18

tertiary consumers

Answer 18

top carnivores; animals that eat other carnivores

Question 19

food chain

Answer 19

path from producers to tertiary consumers

Question 20

food webs

Answer 20

more precisely described path of energy flow
- some animals occupy more than one place

Question 21

biomass

Answer 21

total weight of living/non-living organic material in a given volume
- gain only 10%

Question 22

energy pyramid

Answer 22

each layer represents biomass of a tropic level
- large pyramid
- small pyramid
- inverted pyramid

Question 23

reservoir

Answer 23

where chemicals are stored in a non-living part of the environment

Question 24

carbon

Answer 24

found largely in oceans, atmosphere, terrestrial organisms, fossil deposits

Question 25

nitrogen

Answer 25

involved in amino acids and proteins
mainly found and atmosphere and largely unusable when it’s there

Question 26

phosphorus

Answer 26

mainly in soil
needed for ATP and DNA
increase in pond causes algae bloom

Question 27

eutrophication

Answer 27

build-up of nutrients, (nitrogen and phosphorus) in an ecosystem

Question 28

niche

Answer 28

the way an organism utilizes the resources of its environment, including the space it requires, food it consumers and timing of reproduction

Question 29

niche features

Answer 29

1. space an organism requires
2. type and amount of food required
3. timing of reproduction
4. temperature and moisture requirements
5. what organism feeds
6. influence of competitors

Question 30

fundamental niche

Answer 30

full range of conditions under which the organism could potentially live

Question 31

realized niche

Answer 31

subset of the fundamental niche in which the organism actually thrives

Question 32

coevolved

Answer 32

2 traits evolve together

Question 33

2 ways competition can end (+/-)

Answer 33

1. competitive exclusion: one species uses resources more efficiently and other species is driven to local extinction
2. resource partitioning: each species alters use of niche, dividing resources
   - accompanied by character displacement

Question 34

character displacement

Answer 34

evolutionary divergence in one or both species

Question 35

predation

Answer 35

interaction between 2 species in which one eats the other

Question 36

2 categories of defense against predators

Answer 36

1. physical defenses: mechanical, chemical, warning coloration (mimicry), and camouflage mechanism
2. behavioral defenses: hiding/escaping, alarm calling/fighting back

Question 37

parasitism

Answer 37

symbiotic relationship where one organism benefits while other is harmed

Question 38

2 types of parasitism

Answer 38

1. ectoparasites (outside)
2. endoparasites (inside)

Question 39

mutualism

Answer 39

both species benefit

Question 40

commensalism

Answer 40

one is benefitting and the other isn’t affected

Question 41

succession

Answer 41

process of nature reclaiming an area and of communities gradually changing over time

Question 42

2 types of succession

Answer 42

1. primary succession: occurs when process starts with no life/soil
2. secondary succession: begins when place has established habitat is disturbed but some life and soil remain

Question 43

colonizers

Answer 43

first arrivals in lifeless, soil-less area
usually bacteria or fungi

Question 44

climax community

Answer 44

stable self-sustaining community with longer living, larger species which outcompete colonizers

Question 45

keystone species

Answer 45

unusually large influence on presence or absence of numerous other species in community