Text Chapter 15: Ecology- Communities

Question 1

How interactions between populations can affect the size and composition of the community

Answer 1

predator-prey population cycles follow the same pattern

Question 2

Three Major Types of Interactions in Communities

Answer 2

competition, predation, symbiosis

Question 3

Keystone Species

Answer 3

a plant or animal that helps maintain the diversity and size of other populations

Question 4

Competitive Exclusion

Answer 4

two species competing for the same resource cannot coexist at constant population values, if other ecological factors remain constant

Question 5

Resource Partitioning

Answer 5

when species divide a niche to avoid competition for resources

Question 6

Effects of Predation on a Community

Answer 6

eliminates old and weak individuals, regulates numbers of both predators and prey, coevolution of predators and prey, regulates diversity of populations in community

Question 7

Succession

Answer 7

predictable sequence of changes in a vegetation type over time after a disturbance

Question 8

Situations Where Succession is not Completed

Answer 8

Mount St. Helens eruption

Question 9

Affects of Human Activity on Succession

Answer 9

humans disrupt succession by clearing land, destroying habitats, etc.

Question 10

Ecological Niche

Answer 10

total way of life of all members of a species- habitat, physiological needs including temperature, moisture, and nutrients, behavior, interactions with other species

Question 11

Fundamental Niche

Answer 11

full range of environmental conditions under which species can live

Question 12

Realized Niche

Answer 12

reduced niche due to competition

Question 13

Symbiosis

Answer 13

interaction between two different organisms living in close physical association

Question 14

Commensalism

Answer 14

one helped, other neither helped nor harmed

Question 15

Mutualism

Answer 15

both helped

Question 16

Parisitism

Answer 16

one helped, other harmed

Question 17

Primary Succession

Answer 17

occurs in barren environment with no pre-existing ecosystem

Question 18

Secondary Succession

Answer 18

new community develops after disturbance of existing ecosystem

Question 19

Pioneer Species

Answer 19

tolerate environmental extremes, r-selected species predominate- (high reproductive rates, plants with seeds that spread easily), poor competitors in established communities

Question 20

Climax Community

Answer 20

stable community at endpoint of succession, suited to specific environmental conditions, k-selected species predominant