Ch. 54

Question 1

What is a biological community?

Answer 1

biological community:
the assembly of various specie populations living close enough for potential interaction

Question 2

Give an example of a biological community.

Answer 2

the animals and plants that surround a water hole in South Africa are part a savanna community

Question 3

What are interspecific interactions?

Answer 3

relationships between species in a community;
they affect species survival and reproduction

Question 4

Give some examples of interspecific interactions.

Answer 4

competition, predation, herbivory, symbiosis (parasitism, mutualism, and commensalism), and disease

Question 5

What is the competitive exclusion principal?

Answer 5

that two species competing for the same limiting resources cannot coexist in the same place

Question 6

What is interspecific competition?

Answer 6

when species compete for a resource in short supply; it can be detrimental to both species (–/–)

Question 7

What is competitive exclusion?

Answer 7

the local elimination of competing species;
can occur as a result of strong competition

Question 8

What is an ecological niche? (aka how does the specie survive?)

Answer 8

The total of a species’ use of biotic and abiotic sources

Question 9

What is a fundamental niche?

Answer 9

A place where a species COULD survive

Question 10

What is a realized niche?

Answer 10

A place where a species actually survives/resides

Question 11

Are fundamental and realized niche always the same?

Answer 11

No, because of competition

Question 12

Can similar species coexist in a community?

Answer 12

Yes, if there are one or more significant differences in their niches and with the help of resource partitioning

Question 13

What is resource partitioning?

Answer 13

The differentiation of ecological niches; it enables similar species to coexist in a community

Question 14

Predation

Answer 14

The interaction where one species, the predator, kills and eats the other species, the prey

Question 15

What adaptations do prey species develop?

Answer 15

Defensive adaptions, or behavioral defenses; includes hiding, fleeing, self-defense, and alarm calls

Question 16

What adaptations do predator species develop?

Answer 16

Feeding adaptations; includes claws, teeth, fangs, stingers, and poison

Question 17

What are the four types of adaptations?

Answer 17

Defensive (prey), feeding (predator), morphological (structural), physiological defense (cells or tissues)

Question 18

What trait do animals with effective chemical defense exhibit?

Answer 18

Aposematic coloration - bright warning coloration; makes predators cautious of them as preys

Question 19

Herbivory

Answer 19

An interaction in which an herbivore eats part of a plant or alga; caused evolution of plant mechanical and chemical defenses, and the resulting adaptations by herbivores

Question 20

Parasitism

Answer 20

Where one organism, the parasite, derives nourishment from another organism, the host, which is harmed in the process

Question 21

Pathogens

Answer 21

Disease-causing agents that are typically bacteria, viruses, or protists

Question 22

Mutualism (mutualistic symbiosis)

Answer 22

An interspecific interaction that benefits both species

Question 23

Commensalism

Answer 23

Where one species benefits and the other is unaffected; not as common in nature

Question 24

What is coevolution?

Answer 24

Evolutionary adaptations done in response to two interacting species; little evidence for this in most interspecific interactions

Question 25

Name two fundamental features of a community structure.

Answer 25

Species diversity and feeding relationships

Question 26

Species diversity

Answer 26

the variety of organisms that make up the community; has two parts - species richness and relative abundance

Question 27

Species richness

Answer 27

the total number of different species in the community

Question 28

Relative abundance

Answer 28

the proportion each species represents of the total individuals in the community

Question 29

What is a monoculture

Answer 29

a community with no species diversity

Question 30

True or False: if two species have the same species richness, they must have the same relative abundance

Answer 30

False, they can have different relative abundance

Question 31

Trophic Structure

Answer 31

the feeding relationships between organisms in a community; a key factor in community dynamics; link by food chains from producers to top carnivores

Question 32

What are the five levels of a general food chain? (smallest to largest)

Answer 32

Primary producers (plant) primary consumers (herbivore) secondary consumers (carnivore) tertiary consumers (carnivore) quaternary consumers (carnivore)

Question 33

Food webs

Answer 33

a branching good chain with complex trophic (feeding) interactions

Question 34

What is the arrow rule?

Answer 34

the arrows go the way the energy flows

Question 35

Difference between a food chain and a food web?

Answer 35

Food web is the entirety of the energy transfers (through consuming) in a community, but a food chain is usually only a few links of a food web long

Question 36

What is the energetic hypothesis?

Answer 36

says that length is limited by inefficient energy transfer

Question 37

What is the dynamic stability hypothesis?

Answer 37

says that long food chains are less stable than short ones

Question 38

Is there more data that supports the energetic hypothesis or the dynamic stability hypothesis?

Answer 38

the energetic hypothesis

Question 39

Dominant species

Answer 39

those that are most abundant or have the highest biomass; they exert powerful control over the occurrence and distribution of other species; said to be most competitive in exploiting species and most successful at avoiding predators

Question 40

Compare and contrast keystone and dominant species

Answer 40

Similarities: both exert strong control on a community Differences: keystone species are not necessarily abundant in a community like dominant species are

Question 41

_____ influences species diversity and composition.

Answer 41

disturbance

Question 42

what is the nonequilibrium model

Answer 42

describes communities as constantly changing after being disrupted by disturbances

Question 43

What is disturbance?

Answer 43

an event that changes a community, removes organisms from it, and alters resource availability; can often times be necessary ex: fire

Question 44

Intermediate disturbance hypothesis

Answer 44

suggests that moderate levels of disturbance can foster higher diversity than low levels of disturbance

Question 45

Ecological succession

Answer 45

the sequence of community and ecosystem changes after a disturbance

Question 46

Where does primary succession occur

Answer 46

where no soil exists when succession begins

Question 47

Where does secondary succession occur

Answer 47

in an area where soil remains after a disturbance

Question 48

Pioneer species

Answer 48

species that are early arrivals to the ecosystem and have remained there for long periods of time

Question 49

Name three ways that pioneer species can affect later-arriving species

Answer 49

- can facilitate appearance of later species by making the environment favorable - can inhibit establishment of later species - can tolerate later species but have no impact on them

Question 50

Areas with periodic fires are most likely to have what kind of succession?

Answer 50

secondary

Question 51

Areas affected by a volcanic eruption are most likely to be have what kind of succession?

Answer 51

primary

Question 52

Name 2 key factors correlated with a community's species diversity

Answer 52

geographic location and size