community ecology

Question 1

what is a biological community?

Answer 1

is an assembly of populations that live close enough together for possible interactions

Question 2

can ecologically similar species live together?

Answer 2

yes, as long as they have niches with 1+ differences

Question 3

what is a habitat?

Answer 3

• a place where an organism lives
• has physical and chemical components
• shared with other species

Question 4

what is a niche?

Answer 4

• specific role that a species takes in its community

- total use of biotic and abiotic elements of a particular population

Question 5

what is an interspecific interaction, what does it have an effect on?

Answer 5

relationships/interactions between members of a community. it has an effect on the survival and reproduction (evolution) of species

Question 6

interspecific interaction: competition
what is it, who does it harm/help?
give example

Answer 6

• /-
• species compete for limited resources
• usually detrimental to both
  eg. 2 species of eat same prey -> change eating times, or one gets eliminated

Question 7

interspecific interaction: predation
what is it, who does it harm/help?
give example

Answer 7

+/-

• predator eats prey
• predator benefits, prey dies
  eg. wolves eat deers

Question 8

interspecific interaction: herbivory
what is it, who does it harm/help?
give example

Answer 8

+/-

• herbivore eats plant/algae
• herb benefits, plants dies
• subset of predation/parasitism
  eg. deers eat grass

Question 9

interspecific interaction: parasitism
what is it, who does it harm/help?
give example

Answer 9

+/-
-One organism, the parasite, derives its nourishment from another organism, its host, which is harmed in the
process
-eg. tick on an animal

Question 10

interspecific interaction: mutualism
what is it, who does it harm/help?
give example

Answer 10

+/+

• both species live closely together and benefit
  eg. lichen, mycorrhizae, digestive bacteria

Question 11

interspecific interaction: commensalism
what is it, who does it harm/help?
give example

Answer 11

+/0

• species that live closely together where one benefits at no harm/gain to another
  eg. tree frogs hide in plants

Question 12

what is resource partitioning, give example?

Answer 12

when competing species share a resource, but alter how they use it
eg. hunting at different time, shade vs sun

Question 13

what is competitive exclusion, give example?

Answer 13

when species are competing for the same niche, but one is better and the other dies out

Question 14

what is cryptic colouration, give example?

Answer 14

when species develops a morphological adaptation to look like something else, ie. camouflage
eg. a moth that has same colour pattern as bark of a tree

Question 15

what is aposematic colouration, give example?

Answer 15

typically found in those with a chemical defense -> bright warning colours
eg. brightly coloured poisonous frogs

Question 16

what is batesian mimicry, what is an example?

Answer 16

• when a harmless species mimicks a harmful species

eg. moth eggs that look like a snake

Question 17

what is mullerian mimicry, what is an example?

Answer 17

a form of mimicry in which two or more noxious animals develop similar appearances as a shared protective device, the theory being that if a predator learns to avoid one of the noxious species, it will avoid the mimic species as well
-eg. many butterflies share similar orange/red/black coloration

Question 18

what is an ectoparasite, give an example

Answer 18

ectoparasite is one that lives on external surface of host

eg. lice, fleas

Question 19

what is an endoparasite, give an example

Answer 19

endoparasite lives on the inside of host

eg. hookworm

Question 20

what is obligate mutualism, give an example

Answer 20

is a mutualism in which both need the other to survive

eg. microbes that live in the reticulum chamber of a cows stomach -> digests cellulose for cow, microbe gets food

Question 21

what is a facultative mutualism, give an example

Answer 21

is a mutualism where together both species benefit, but they could both survive on their own
eg

Question 22

what is a trophic structure?

Answer 22

The feeding relationships between organisms in a community

Question 23

what is the producer’s role in the trophic structure? how do they do this?

Answer 23

to support the rest of the community
-synthesize sugars and other organic compounds for
their own growth
-using inorganic compounds (e.g. CO2 and H2O)and
an external energy source (e.g. sunlight)

Question 24

what are consumers? What kind of consumers are there in a trophic structure, what do they eat?

Answer 24

-consumers obtain their organic compounds from other
organisms in the trophic structure
1. Primary consumers
-consume producers
2. secondary producers
-consume primary consumers

Question 25

what are food chains?

Answer 25

food chains are pathways in energy is transferred from producers to consumers

Question 26

what are food webs?

Answer 26

food webs are interconnected food chains, with complex trophic interactions -shows species can play more than one role in a community

Question 27

what is trophic efficiency?

Answer 27

efficiency with which food energy is converted to biomass in each link of the trophic structure

Question 28

how much energy is not transferred between trophic levels? what is the rule for trophic efficiency, what does it mean?

Answer 28

- about 80-95% of energy is NOT transferred - there is a 10% rule for trophic efficiency. - this means only 10% of energy is transferred between levels, and that at each level, consumers need to consumer more

Question 29

give an example food chain, with 10% rule

Answer 29

1. Producer -> grass -> 20,000J 2. Primary consumer -> grasshopper -> 2000J 3. Secondary consumer -> frog -> 200J 4. Tertiary consumer -> snake -> 20J

Question 30

what is an ecosystem?

Answer 30

the community of organisms in an area and the physical factors with which they interact

Question 31

what affects primary productivity?

Answer 31

Abiotic factors -> eg. sunlight, water, nutrients

Question 32

what is symbiosis?

Answer 32

Two or more species living in direct and intimate | contact with one another

Question 33

what do omnivores feed on?

Answer 33

feed on both producers and consumers

Question 34

what do decomposers consume?

Answer 34

are consumers of non-living organic matter

Question 35

what two factors effect distribution of organisms?

Answer 35

biotic (predators, competition, symbiosis) | abiotic (water availability, temperature, wind, rocks)

Question 36

what is climate?

Answer 36

- water and temperature | - Long-term prevailing weather conditions in an area

Question 37

what is a microclimate?

Answer 37

- consists of very fine local patterns | - E.g. underneath a fallen log

Question 38

what effect does the sun have on climate?

Answer 38

The sun affects: - temperature variations - cycles of air movement - evaporation and precipitation of water

Question 39

the dynamics of an ecosystem are determined by what 2 factors?

Answer 39

ENERGY FLOW AND | CHEMICAL CYCLING